ci: Scorecard, and actionlint and zizmor on the workflows

.github/workflows/ci.yml

@@ -1,7 +1,7 @@
 # The pull-request check: is ffmpeg-build.yml valid, does ffmpeg.lock cover it, can every target be planned? It builds
 # nothing (the daily release builds and tests every target before it publishes, and keeps a release that fails a
 # draft), so it takes a minute. It merges the lock updates (update-lock.yml) and Dependabot's PRs once it passes.
-# `result` is the check the main ruleset requires.
+# The lint job checks the workflows (actionlint, zizmor). `result` is the check the main ruleset requires.
 name: CI
 on:
   pull_request:
@@ -19,18 +19,35 @@ jobs:
     uses: devenvy/ffmpeg-build/.github/workflows/check.yml@52201a1204772caf79156ced0954c25407f6b433 # v0.0.5
     permissions:
       contents: read
+  # the workflows: actionlint (mistakes) and zizmor (GitHub Actions security)
+  lint:
+    runs-on: ubuntu-24.04
+    timeout-minutes: 10
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - name: actionlint
+        uses: raven-actions/actionlint@3d39aea434753780c3b3d4a1a31c854b4dbf49d7 # v2.2.0
+      - name: zizmor
+        uses: zizmorcore/zizmor-action@cc914d7f3750a2d13d75c7f184a1060aa0e9d482 # v0.6.4
+        with:
+          advanced-security: false # fail the job on findings instead of uploading SARIF
   # one check for the main ruleset to require, whatever ran
   result:
-    needs: check
+    needs: [check, lint]
     if: always()
     runs-on: ubuntu-24.04
     timeout-minutes: 5
     permissions: {}
     steps:
-      - name: the check passed
+      - name: the check and lint passed
         env:
           CHECK: ${{ needs.check.result }}
-        run: test "${CHECK}" = success
+          LINT: ${{ needs.lint.result }}
+        run: test "${CHECK}" = success && test "${LINT}" = success
   merge:
     needs: result
     uses: devenvy/ffmpeg-build/.github/workflows/automerge.yml@52201a1204772caf79156ced0954c25407f6b433 # v0.0.5

.github/workflows/scorecard.yml

@@ -0,0 +1,35 @@
+name: Scorecard
+
+# OpenSSF Scorecard: supply-chain security checks, published to the public Scorecard API (for
+# the badge) and uploaded to code scanning. Its own workflow because publishing requires that
+# no other job in the workflow holds id-token: write and that there are no workflow-level
+# write permissions, env or defaults.
+on:
+  push:
+    branches: [main]
+  schedule:
+    - cron: '41 6 * * 1'
+
+permissions: {}
+
+jobs:
+  analysis:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    permissions:
+      contents: read
+      actions: read
+      security-events: write # upload results to code scanning
+      id-token: write # publish results to the Scorecard API
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - uses: ossf/scorecard-action@fa7117db83c52d787ae5a89f350999701505d78e # v2.5.0
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          publish_results: true
+      - uses: github/codeql-action/upload-sarif@24c54180a607b1449ed407dd24f251e4e9147c8d # v4.38.3
+        with:
+          sarif_file: results.sarif