Update Trivy workflow to remove image build step

Removed the Docker image build step and updated Trivy scan configuration.

Author: Hurleveur

.github/workflows/trivy.yml

@@ -29,14 +29,11 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Build an image from Dockerfile
-        run: |
-          docker build -t docker.io/my-organization/my-app:${{ github.sha }} .
-
       - name: Run Trivy vulnerability scanner
         uses: aquasecurity/trivy-action@7b7aa264d83dc58691451798b4d117d53d21edfe
         with:
-          image-ref: 'docker.io/my-organization/my-app:${{ github.sha }}'
+          scan-type: repo          # or "fs"
+          scan-ref: .              # current repo
           format: 'template'
           template: '@/contrib/sarif.tpl'
           output: 'trivy-results.sarif'