ci: add trivy scanning workflow (#466)

this workflow scans and uploads the results into the protected Github
Security tab for review.

.github/workflows/trivy.yml

@@ -0,0 +1,41 @@
+# trivy ci workflow
+name: trivy
+
+on:
+  workflow_dispatch:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ "main" ]
+  schedule:
+    - cron: '00 12 * * *'
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    permissions:
+      contents: read # for actions/checkout to fetch code
+      security-events: write # for github/codeql-action/upload-sarif to upload SARIF results
+      actions: read # only required for a private repository by github/codeql-action/upload-sarif to get the Action run status
+    name: Check
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        
+      - name: Run Trivy vulnerability scanner
+        uses: aquasecurity/trivy-action@master
+        with:
+          scan-type: 'fs'
+          ignore-unfixed: true
+          format: 'sarif'
+          output: 'trivy-results.sarif'
+          severity: 'CRITICAL,HIGH'
+
+      - name: Upload Trivy scan results to GitHub Security tab
+        uses: github/codeql-action/upload-sarif@v3
+        with:
+          sarif_file: 'trivy-results.sarif'