I'm not familiar with Pygithub API, I have done the "clone" action, but I don't know how to "pull" to update repositories that already cloned.
I have "clone" repositories from github
client = Github(base_url=f'https://{hostname}/api/v3', login_or_token=token)
repos = client.get_organization(organization).get_repos()
for repo in repos:
Repo.clone_from(remote, local)