[llvm] [CI][format] Explicitly pass extensions to git-clang-format (PR #95794)

[Tobias Hieta via llvm-commits]

tru wrote:

Please run black, other than that LGTM! It's a bit strange that even if you pass clang-format an explicit list it still filters it, but hey glad we have this workaround   

https://github.com/llvm/llvm-project/pull/95794