Add concurrency limits to artifact publication workflow

Author: sd109

.github/workflows/build-push-artifacts.yml

@@ -9,6 +9,12 @@ on:
     tags:
       - "*"
 
+# Use the head ref for workflow concurrency, with cancellation
+# This should mean that any previous workflows for a PR get cancelled when a new commit is pushed
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref }}
+  cancel-in-progress: true
+
 jobs:
   publish_images:
     uses: ./.github/workflows/build-push-images.yml