Fixes a failure case where git user and email credentials are missing during the commit signing. New inputs:
config_git_credentials- Default 'true'git_user- Default 'Action - Fork Sync'git_email- Default 'action@github.com'
Set these to custom values if necessary. On action complete, the config resets to previous values (even if the values are empty). Set config_git_credentials to 'false' to skip this step and use existing credentials.