feat: add dynamic build branch argument for Docker image creation

.github/workflows/docker-publish.yml

@@ -70,6 +70,7 @@ jobs:
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
+          build-args: BUILD_BRANCH=${{ github.ref_name }}
 
       # Sign the resulting Docker image digest except on PRs.
       # This will only write to the public Rekor transparency log when the Docker