[clang-tools-extra] [clang-tidy] Catch <cctype> function args in bugprone-signed-char-misuse (PR #211403)

[Zeyi Xu via cfe-commits]

zeyi2 wrote:

Also, if AI was used in this PR. Please disclose it according to [LLVM AI Policy](https://llvm.org/docs/AIToolPolicy.html)

https://github.com/llvm/llvm-project/pull/211403