[llvm] [workflows] Add post-commit job that periodically runs the clang static analyzer (PR #94106)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 approved this pull request.

LGTM.

It seems like we aren't utilizing all the time now (~180/360 minutes). I think that should probably be fine. We can always adjust limits later as we have a better feel for the job duration.

https://github.com/llvm/llvm-project/pull/94106