[clang] [clang-tools-extra] [clangd] Fixed signature help for static call operator (C++23) (PR #199192)

[via cfe-commits]

https://github.com/timon-ul requested changes to this pull request.

I am a bit confused as to why we now have code changes in both places, `SemaCodeComplete.cpp` and `SemaOverload.cpp`, just the ones in `SemaOverload.cpp` should be enough.

https://github.com/llvm/llvm-project/pull/199192