lowercase by command

.github/workflows/publish_docker_image.yml

@@ -32,6 +32,9 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
 
+      - name: Set image name to lowercase
+        run: echo "IMAGE_NAME_LOWER=$(echo '${{ github.repository }}' | tr '[:upper:]' '[:lower:]')" >> $GITHUB_ENV
+
       # Workaround: https://github.com/docker/build-push-action/issues/461
       - name: Setup Docker buildx
         uses: docker/setup-buildx-action@v2
@@ -49,8 +52,7 @@ jobs:
       - name: Print environment variables
         run: |
           echo "Registry: $REGISTRY"
-          echo "Image Name: $IMAGE_NAME"
-
+          echo "Image Name: $IMAGE_NAME_LOWER"
 
       # Build and push Docker image with Buildx (don't push on PR)
       # https://github.com/docker/build-push-action
@@ -61,6 +63,6 @@ jobs:
           context: ./OEDS_explorer
           platforms: linux/amd64,linux/arm64/v8
           push: ${{ github.event_name != 'pull_request' }}
-          tags: ${{ env.REGISTRY }}/${{ github.repository | lower }}:latest
+          tags: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME_LOWER }}:latest
           cache-from: type=gha
           cache-to: type=gha,mode=max