[llvm] [workflows] Rework pre-commit CI for the release branch (PR #92058)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 commented:

Is it possible to split this into multiple PRs? This is a pretty big diff to review at the same time. I think some things could naturally be separate PRs like the individual actions/integration into the CI tests workflow.

https://github.com/llvm/llvm-project/pull/92058