Action update.

.github/workflows/update_readme.yml

@@ -21,4 +21,4 @@ jobs:
         git config --global user.email 'github-actions[bot]@users.noreply.github.com'
         git add README.md
         git commit -m "Update Docker tag in README to ${{ github.ref_name }}"
-        git push
+        git push origin HEAD:main