ci: add OpenSSF Scorecard analysis

.github/workflows/scorecard.yml

@@ -0,0 +1,48 @@
+# OpenSSF Scorecard supply-chain security analysis.
+name: Scorecard supply-chain security
+
+on:
+  branch_protection_rule:
+  schedule:
+    - cron: '5 23 * * 5'
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+permissions: read-all
+
+jobs:
+  analysis:
+    name: Scorecard analysis
+    runs-on: ubuntu-latest
+    permissions:
+      security-events: write
+      id-token: write
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+
+      - name: Run analysis
+        uses: ossf/scorecard-action@4eaacf0543bb3f2c246792bd56e8cdeffafb205a # v2.4.3
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          # Publishing only succeeds on the default branch. PR and manual runs
+          # still validate the analysis and produce SARIF without publishing.
+          publish_results: ${{ github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch) }}
+
+      - name: Upload SARIF artifact
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: scorecard-results
+          path: results.sarif
+          retention-days: 5
+
+      - name: Upload to code scanning
+        uses: github/codeql-action/upload-sarif@e4fba868fa4b1b91e1fdab776edc8cfbe6e9fb81 # v4.37.3
+        with:
+          sarif_file: results.sarif