build arm

Author: pbauer

.github/workflows/backend.yml

@@ -159,7 +159,9 @@ jobs:
       - name: Build and push
         uses: docker/build-push-action@v5
         with:
-          platforms: linux/amd64
+          platforms:
+            - linux/amd64
+            - linux/arm64
           context: backend
           file: backend/Dockerfile
           push: ${{ github.event_name != 'pull_request' }}