ci: add Trivy fallback DB repositories

Just adding these now to try to avoid people hitting the Trivy rate limiting issues later.

.github/workflows/trivy.yml

@@ -62,12 +62,14 @@ jobs:
           tags: "spacelift-promex:${{ github.sha }}"
 
       - name: Run Trivy vulnerability scanner
-        uses: aquasecurity/trivy-action@master
+        uses: aquasecurity/trivy-action@0.27.0
         with:
           image-ref: "spacelift-promex:${{ github.sha }}"
           format: "sarif"
           output: "trivy-results.sarif"
           severity: "CRITICAL,HIGH"
+        env:
+          TRIVY_DB_REPOSITORY: ghcr.io/aquasecurity/trivy-db,public.ecr.aws/aquasecurity/trivy-db
 
       - name: Upload Trivy scan results to GitHub Security tab
         uses: github/codeql-action/upload-sarif@v3