fix backport ready for PyGithub 2

backport.py

@@ -90,15 +90,15 @@ def git(args: list[str], cd: Optional[str] = None) -> None:
     print('')
 
 
-class App(object):
+class App:
     def __init__(
             self, token: str, organ_name: str, repo_name: str,
             debug: bool = False):
         assert isinstance(organ_name, str)
         assert isinstance(repo_name, str)
         self.repo_name = repo_name
         self.organ_name = organ_name
-        self.g = github.Github(token)
+        self.g = github.Github(auth=github.Auth.Token(token))
         self.repo = self.g.get_repo('{}/{}'.format(organ_name, repo_name))
         self.user_name = self.g.get_user().login
         self.debug = debug