.github: Bump actions/checkout from 4 to 5

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 5.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v5)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/buf-push.yaml

@@ -11,7 +11,7 @@ jobs:
   push:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
         # This step sets up the variable steps.buf-version.outputs.v
         # to contain the version of Buf (e.g. v1.36.0) from go.mod.

.github/workflows/buf-update.yaml

@@ -11,7 +11,7 @@ jobs:
     env:
       GITHUB_TOKEN: ${{ github.token }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - name: Run 'buf update'
         run: |

.github/workflows/buf-validate.yaml

@@ -13,7 +13,7 @@ jobs:
   validate:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       # This step sets up the variable steps.buf-version.outputs.v
       # to contain the version of Buf (e.g. v1.36.0) from go.mod.

.github/workflows/lint.yml

@@ -9,7 +9,7 @@ jobs:
   golangci-lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: actions/setup-go@v5
         with:
           go-version-file: 'go.mod'

.github/workflows/test.yml

@@ -9,7 +9,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - name: Set up Go
         uses: actions/setup-go@v5

.github/workflows/validate-generated-files.yml

@@ -9,7 +9,7 @@ jobs:
   validate-generated-files:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - name: Set up Go
         uses: actions/setup-go@v5