[clang-tools-extra] [clang-tidy] Add llvm-regex check (PR #207407)

[Zeyi Xu via cfe-commits]

zeyi2 wrote:

Also please note that the LLVM 23.1.x release is in about two weeks, so we probably won’t be able to land this before the release.

https://github.com/llvm/llvm-project/pull/207407