Error: The process '/usr/bin/git' failed with exit code 128

The `set-output` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

Your repository allows merge commits and rebase merging. However, Backport only supports rebased and merged pull requests with a single commit and squashed and merged pull requests. Consider only allowing squash merging. See https://help.github.com/en/github/administering-a-repository/about-merge-methods-on-github for more information.