Add support for 'visibility' attribute when editing a repo

[lunim]

GitHub Enterprise cloud and On-Premise have support for the "Internal" status. Please add support for setting this attribute.

Name	Type	In	Description
visibility	string	body	Can be public or private. If your organization is associated with an enterprise account using GitHub Enterprise Cloud or GitHub Enterprise Server 2.20+, visibility can also be internal. The visibility parameter overrides the private parameter when you use both along with the nebula-preview preview header.

https://docs.github.com/en/rest/reference/repos#update-a-repository