Set context for docker build to root directory.

Author: lmarini

.github/workflows/backend.yaml

@@ -86,6 +86,7 @@ jobs:
         uses: docker/build-push-action@v3
         with:
           context: .
+          file: ./backend/Dockerfile
           platforms: linux/amd64,linux/arm64
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.backendMeta.outputs.tags }}
@@ -96,19 +97,19 @@ jobs:
         uses: docker/build-push-action@v3
         with:
           context: .
+          file: ./backend/heartbeat.Dockerfile
           platforms: linux/amd64,linux/arm64
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.heartbeatMeta.outputs.tags }}
-          file: ./backend/heartbeat.Dockerfile
           labels: ${{ steps.heartbeatMeta.outputs.labels }}
 
       -
         name: Build and push
         uses: docker/build-push-action@v3
         with:
           context: .
+          file: ./backend/messages.Dockerfile
           platforms: linux/amd64,linux/arm64
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.messagesMeta.outputs.tags }}
-          file: ./backend/messages.Dockerfile
           labels: ${{ steps.messagesMeta.outputs.labels }}