fix backport ready for PyGithub 2

[kmaehashi]

https://github.com/PyGithub/PyGithub/releases/tag/v1.59.0

This release introduces new way of authentication. All authentication-related arguments github.Github(login_or_token=…, password=…, jwt=…, app_auth=…) and github.GithubIntegration(integration_id=…, private_key=…, jwt_expiry=…, jwt_issued_at=…, jwt_algorithm=…) are replaced by a single auth=… argument. Module github.Auth provides classes for all supported ways of authentication: Login, Token, AppAuth, AppAuthToken, AppInstallationAuth, AppUserAuth. Old arguments are deprecated but continue to work. They are scheduled for removal for version 2.0 release.

[kmaehashi]

This line is just a cleanup, unrelated to PyGithub :)

[toslunar]

LGTM