Build multi-arch containers

.github/workflows/docker-publish.yml

@@ -39,6 +39,9 @@ jobs:
         if: github.event_name != 'pull_request'
         uses: sigstore/[email protected]
 
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
       # Set up BuildKit Docker container builder to be able to build
       # multi-platform images and export cache
       # https://github.com/docker/setup-buildx-action
@@ -75,6 +78,7 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=gha
           cache-to: type=gha,mode=max
+          platforms: linux/amd64,linux/arm64,linux/arm/v7,linux/arm/v8,darwin
 
       # Sign the resulting Docker image digest except on PRs.
       # This will only write to the public Rekor transparency log when the Docker