Pass in option to use global git config

[daniddelrio]

Proposed change

With this change, one can pass --use-global-git-config to the auto-pr pull command so that the default behavior to use the primary email of the authenticated Github user is overridden by using the global git config.

If the repos have already been pulled and you would like to run the auto-pr with your global config, you would need to run auto-pr pull --update-repos --use-global-git-config before running auto-pr run to override the config of your newly pulled repos.

How to test the change

poetry install
poetry run auto-pr -w <PATH_TO_YOUR_AUTOPR_CONFIG> pull --use-global-git-config --update-repos

in order to change the config on your already pulled repos

Checklist

• Tests have been added to verify that the new code works (if possible)
• Documentation has been updated to reflect changes
• CHANGELOG.md has been updated to reflect changes