ci: remove trivy-action (#7961)

.github/workflows/trivy-scan.yaml

@@ -1,35 +0,0 @@
-name: Trivy Nightly Scan
-on:
-  schedule:
-    - cron: '0 2 * * 5'  # Run at 2AM UTC on every Friday
-
-permissions: read-all
-jobs:
-  nightly-scan:
-    name: Trivy Scan nightly
-    strategy:
-      fail-fast: false
-      matrix:
-        # It will test for only the latest version as older version is not maintained
-        versions: [latest]
-    permissions:
-      security-events: write  # for github/codeql-action/upload-sarif to upload SARIF results
-
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout code
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
-        with:
-          persist-credentials: false
-      - name: Run Trivy vulnerability scanner
-        uses: aquasecurity/trivy-action@57a97c7e7821a5776cebc9bb87c984fa69cba8f1  # master
-        with:
-          image-ref: 'docker.io/coredns/coredns:${{ matrix.versions }}'
-          severity: 'CRITICAL,HIGH'
-          format: 'sarif'
-          output: 'trivy-results.sarif'
-
-      - name: Upload Trivy scan results to GitHub Security tab
-        uses: github/codeql-action/upload-sarif@38697555549f1db7851b81482ff19f1fa5c4fedc  # v4.34.1
-        with:
-          sarif_file: 'trivy-results.sarif'