Support for fine grained Personal Access Tokens (PAT v2)

[rahim]

See https://github.blog/2022-10-18-introducing-fine-grained-personal-access-tokens-for-github/

At the time of writing Github are still working on GraphQL support for the newer fine grained access tokens which is likely to be a significant obstacle until resolved. Even github-cli support is blocked by this.

I'm working within an organisation that's already moving to retire use of classic tokens.

Fine grained tokens (with appropriate guidance for end users as to what permissions are needed) seems like a good fit for Trailer. My understanding is its behaviour is entirely read-only, so tokens could be much more narrowly scoped than today.