[clang-tools-extra] Add option to exclude headers from clang-tidy analysis (PR #91400)

[Nick Desaulniers via cfe-commits]

nickdesaulniers wrote:

hmm...thanks for testing it out.  I think something else must be going wrong for me.
I'm running clang-tidy via bazel via [bazel_clang_tidy](https://github.com/erenon/bazel_clang_tidy) which is perhaps complicating things.  It seems to be running on my .h files itself(?) as its finding implicit includes (good), but then perhaps is ignoring ExcludeHeaderFilterRegex.  I wonder if https://github.com/erenon/bazel_clang_tidy/pull/79 is related...

https://github.com/llvm/llvm-project/pull/91400