Tweak container build GitHub Action

.github/workflows/push.yml

@@ -1,12 +1,15 @@
 name: Build and publish
 
 on:
+  # https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#onpushpull_requestbranchestags
   push:
-    branches: [ "main" ]
+    branches:
+      - '**' # all branches; with or without '/'
+      - '!main' # exclude main
     # Publish semver tags as releases.
     tags: [ 'v*.*.*' ]
-  pull_request:
-    branches: [ "main" ]
+  # pull_request:
+  #   branches: [ "main" ]
 
 env:
   # Use docker.io for Docker Hub if empty
@@ -39,6 +42,10 @@ jobs:
       #  with:
       #    cosign-release: 'v2.1.1'
 
+      # https://github.com/docker/setup-qemu-action
+      - 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
@@ -76,8 +83,7 @@ jobs:
         id: build-and-push
         uses: docker/bake-action@v5 #v5.3.0
         with:
-          #push: ${{ github.event_name != 'pull_request' }}
-          push: true
+          push: ${{ github.event_name != 'pull_request' }}
           load: true
           #provenance: true
           #sbom: true