Skip push unless tagged

.github/workflows/image.yml

@@ -111,6 +111,7 @@ jobs:
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Create manifest list and push
+        if: ${{ startsWith(github.ref, 'refs/tags') }}
         working-directory: /tmp/digests
         run: |
           docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \