Support OIDC subjects which reference a GitHub Org and wildcard Repo

[johnstonmatt]

OIDC represents a big improvement in terms of security by reducing the risk of leaked credentials, and at polyseam/cndi we want to bring that value to our users.

In our integration with AWS we are able to specify a trust policy which grants OIDC access for all repos in a given GitHub Organization using a wildcard pattern.

Creating a new OIDC app registration for every repo is such a manual process that I don't think it is sufficiently easy to adopt, and our users will likely continue to use API credentials instead - unless support for wildcard patterns can be added.

[petr-stupka]

related #346