use multiple runners for the multi-arch build

.gitea/workflows/ci.yml

@@ -63,10 +63,14 @@ jobs:
           token: ${{ secrets.CODECOV_TOKEN }}
   build:
     name: Build and push image
-    runs-on: ${{ matrix.runner }}
+    runs-on: ${{ matrix.arch.runner }}
     strategy:
       matrix:
-        runner: [ubuntu-latest, ubuntu-arm-latest]
+        arch:
+          - runner: ubuntu-latest
+            platform: linux/amd64
+          - runner: ubuntu-arm-latest
+            platform: linux/arm64
     permissions:
       packages: write
     needs: tests
@@ -92,17 +96,14 @@ jobs:
             org.opencontainers.image.description=teufa container image
             org.opencontainers.image.source=https://brosner.dev/brosner/teufa
             org.opencontainers.image.licenses=MIT
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@v3
       - name: Setup docker buildx
         uses: docker/setup-buildx-action@v3
       - name: Build image
         uses: docker/build-push-action@v6
-        if: gitea.ref == 'refs/heads/main'
         with:
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           annotations: ${{ steps.meta.outputs.annotations }}
           target: prod
-          platforms: ${{ matrix.runner == 'ubuntu-latest' && 'linux/amd64' || 'linux/arm64' }}
-          push: true
+          platforms: ${{ matrix.arch.platform }}
+          outputs: type=image,push-by-digest=true,name-canonical=true,push=true