Parse commits into the drupal.org format

When we commit the build artifacts to the relevant branch on drupal.org, it would be nice to parse out the authors/co-authors since the last commit and add them in the following format:
`Issue #12345 by author1, author2, author3: Issue title`
This will ensure they get a credit on drupal.org

https://github.com/jsdrupal/admin_ui/blob/8.x-1.x/.github/workflows/sync-repo-push-branch.yml#L36