Shard github activity over multiple GH apps

We would like to be able to install multiple Github apps to a single VCS integration to work around githubs rate limits of 15k request per an hour in a busy monorepo, this pattern is used by other apps such as WIZ, and would allow us to scale without hoping that Github will approve our limits increase

With out this during busy times we see sync operations fail, and missing comments and checks in github

This would also make it easier to manage then knowing what is pinned to what app, and changing the integration on existing stacks can be messy with active stacks.