chore: add openssf scorecard workflow (#359)

Signed-off-by: Jennifer Power <barnabei.jennifer@gmail.com>

.github/workflows/scorecard.yml

@@ -0,0 +1,49 @@
+name: Scorecard analysis workflow
+on:
+  push:
+    # Only the default branch is supported.
+    branches:
+    - main
+  schedule:
+    # Weekly on Saturdays.
+    - cron:  '30 1 * * 6'
+
+permissions: read-all
+
+jobs:
+  analysis:
+    if: github.repository == 'RedHatProductSecurity/trestle-bot'
+    name: Scorecard analysis
+    runs-on: ubuntu-latest
+    permissions:
+      # Needed for Code scanning upload
+      security-events: write
+      # Needed for GitHub OIDC token if publish_results is true
+      id-token: write
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # pin@v4
+        with:
+          persist-credentials: false
+
+      - name: Run analysis
+        uses: ossf/scorecard-action@62b2cac7ed8198b15735ed49ab1e5cf35480ba46 # v2.4.0
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          publish_results: true
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@0b2256b8c012f0828dc542b3febcab082c67f72b # pin@v4
+        with:
+          name: SARIF file
+          path: results.sarif
+          retention-days: 5
+
+      # Upload the results to GitHub's code scanning dashboard (optional).
+      # Commenting out will disable upload of results to your repo's Code Scanning dashboard
+      - name: Upload to code-scanning
+        uses: github/codeql-action/upload-sarif@461ef6c76dfe95d5c364de2f431ddbd31a417628 # v3.26.9
+        with:
+          sarif_file: results.sarif