Enable multi-platform Docker builds in backend CI/CD pipeline

Author: projkov

.github/workflows/backend-ci-cd.yml

@@ -79,6 +79,12 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
       - name: Extract metadata for Docker
         id: meta
         uses: docker/metadata-action@v5
@@ -95,5 +101,6 @@ jobs:
           context: ./backend
           file: ./backend/Dockerfile
           push: true
+          platforms: linux/amd64,linux/arm64
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}