build(deps): Bump actions/checkout from 4 to 6

.github/workflows/bench.yml

@@ -10,7 +10,7 @@ jobs:
   bench:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: "3.11"

.github/workflows/chace.yml

@@ -27,7 +27,7 @@ jobs:
         os: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: System info
         run: uname -a && clang --version

.github/workflows/ci-stack.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 180
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install Verilator and Yosys (RTL gate)
         run: sudo apt-get update -qq && sudo apt-get install -qq -y verilator yosys
@@ -38,7 +38,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 120
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - uses: YosysHQ/setup-oss-cad-suite@v4
         with:
@@ -65,7 +65,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 30
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install clang + C deps
         run: |

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
     timeout-minutes: 20
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install C build dependencies
         run: |
@@ -66,7 +66,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: "3.12"
@@ -95,7 +95,7 @@ jobs:
       matrix:
         python-version: ["3.11", "3.12", "3.13"]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
@@ -145,7 +145,7 @@ jobs:
         os: [ubuntu-latest, macos-latest, windows-latest]
         python-version: ["3.10", "3.11", "3.12", "3.13"]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
@@ -170,7 +170,7 @@ jobs:
   license-check:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: SPDX headers present (python/cos)
         run: |
           python3 <<'PY'
@@ -217,7 +217,7 @@ jobs:
       matrix:
         python-version: ["3.10", "3.11", "3.12", "3.13"]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}

.github/workflows/codeql.yml

@@ -27,7 +27,7 @@ jobs:
       matrix:
         language: [cpp]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v3

.github/workflows/docker-compose-smoke.yml

@@ -19,7 +19,7 @@ jobs:
   compose-smoke:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Smoke test (single-container; /v1/health)
         env:

.github/workflows/docker-fastapi-serve.yml

@@ -21,7 +21,7 @@ jobs:
       contents: read
       packages: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - uses: docker/setup-buildx-action@v3
 

.github/workflows/docker.yml

@@ -24,7 +24,7 @@ jobs:
       packages: write
       id-token: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - uses: docker/setup-qemu-action@v3
 

.github/workflows/merge-gate.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 120
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: "3.12"

.github/workflows/mutation-testing.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 90
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: "3.12"

.github/workflows/publish.yml

@@ -15,7 +15,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: "3.12"

.github/workflows/pypi-semantic-release.yml

@@ -31,7 +31,7 @@ jobs:
       released: ${{ steps.psr.outputs.released }}
       tag: ${{ steps.psr.outputs.tag }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
           persist-credentials: true

.github/workflows/pypi.yml

@@ -18,7 +18,7 @@ jobs:
     name: Build distribution
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: "3.11"
@@ -34,7 +34,7 @@ jobs:
     needs: build
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v5
         with:
           python-version: "3.11"

.github/workflows/red-team.yml

@@ -21,7 +21,7 @@ jobs:
   red-team:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - uses: actions/setup-python@v5
         with:

.github/workflows/release.yml

@@ -19,7 +19,7 @@ jobs:
     name: macOS · universal (arm64 + x86_64)
     runs-on: macos-14
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Build universal binaries
         run: |
           set -eux
@@ -61,7 +61,7 @@ jobs:
             runner: ubuntu-24.04-arm
     runs-on: ${{ matrix.runner }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Build
         run: |
           set -eux
@@ -83,7 +83,7 @@ jobs:
     name: Linux · cos CLI (amd64 tarball)
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Install deps
         run: |
           sudo apt-get update -qq
@@ -109,7 +109,7 @@ jobs:
     runs-on: ubuntu-24.04
     needs: [binaries-linux]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: docker/setup-qemu-action@v3
       - uses: docker/setup-buildx-action@v3
       - uses: docker/login-action@v3
@@ -138,7 +138,7 @@ jobs:
     needs: [binaries-macos, binaries-linux, linux-cos-cli]
     if: startsWith(github.ref, 'refs/tags/')
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install C build dependencies (bare linux cos attach)
         run: |

.github/workflows/scorecard.yml

@@ -16,7 +16,7 @@ jobs:
       security-events: write
       id-token: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
 

.github/workflows/security.yml

@@ -35,7 +35,7 @@ jobs:
     name: gitleaks (full history)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: gitleaks
@@ -52,7 +52,7 @@ jobs:
         os: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: make harden
         run: make harden
       - name: make hardening-check
@@ -66,15 +66,15 @@ jobs:
         os: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: make sanitize
         run: make sanitize
 
   security-scan:
     name: security-scan (grep fallback + URLs)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: install gitleaks
@@ -89,7 +89,7 @@ jobs:
     name: sbom (CycloneDX 1.5)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: make sbom
         run: make sbom
       - name: upload SBOM artifact
@@ -102,6 +102,6 @@ jobs:
     name: reproducible-build
     runs-on: macos-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: make reproducible-build
         run: make reproducible-build

.github/workflows/shellcheck.yml

@@ -11,7 +11,7 @@ jobs:
   shellcheck:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Install ShellCheck
         run: sudo apt-get update -qq && sudo apt-get install -qq -y shellcheck

.github/workflows/sigma-ci.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - uses: actions/setup-python@v5
         with:

.github/workflows/slsa.yml

@@ -24,7 +24,7 @@ jobs:
     outputs:
       digest: ${{ steps.hash.outputs.digest }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Build hardened v61
         run: make standalone-v61-hardened
       - name: Compute artifact digest