Use GitHub App & OSS API for codeowners tools instead of GitHub PAT

[hallipr]

We still require GitHub PATs to pull team member access for CodeOwners processing. This is because our GH App doesn't have access to Azure org info like team private membership.

OSS Portal has added an API for pulling team membership using our entra app id. This should remove the last use case for GitHub PATs allowing us to move our remaining tools to all GH App tokens and Entra auth.

• Current Branch for azure-sdk-tools

[jeffwilcox]

Any updates on this work, or at least kicking the tires?

[jeffwilcox]

Just checking in...

[weshaggard]

We haven't done this work yet. We currently still using a PAT we manually rotate once a month. We are hoping that a better solution will come along for some of these things before we end up needing to write our own code to mint tokens from a github app inside of our pipelines.

[weshaggard]

Have started converting some usages to the app #13556