fix(ci): convert repository name to lowercase for docker tag

The Docker build was failing with the error "repository name must be lowercase" because the GITHUB_REPOSITORY variable contained uppercase characters.

This commit fixes the issue by adding a step to the docker.yml workflow that converts the repository name to lowercase before it is used in the image tag for the build-push and trivy-scan jobs.

Author: google-labs-jules[bot]

.github/workflows/docker.yml

@@ -34,19 +34,23 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435
 
+      - name: Lowercase repository name
+        id: repo_name
+        run: echo "name=$(echo ${{ github.repository }} | tr '[:upper:]' '[:lower:]')" >> $GITHUB_OUTPUT
+
       - name: Build and push
         uses: docker/build-push-action@263435318d21b8e681c14492fe198d362a7d2c83
         with:
           context: .
           push: true
-          tags: ghcr.io/${{ github.repository }}:${{ github.sha }}
+          tags: ghcr.io/${{ steps.repo_name.outputs.name }}:${{ github.sha }}
           cache-from: type=gha
           cache-to: type=gha,mode=max
 
       - name: Scan for vulnerabilities
         uses: aquasecurity/trivy-action@b6643a29fecd7f34b3597bc6acb0a98b03d33ff8
         with:
-          image-ref: 'ghcr.io/${{ github.repository }}:${{ github.sha }}'
+          image-ref: 'ghcr.io/${{ steps.repo_name.outputs.name }}:${{ github.sha }}'
           format: 'table'
           exit-code: '1'
           ignore-unfixed: true