[clang] Update GoogleTest to v1.14.0 (PR #65823)

[Fangrui Song via cfe-commits]

MaskRay wrote:

Thank you for the change! `ninja check-llvm check-clang check-clang-tools check-flang check-mlir check-lld check-polly` parses.

> The GoogleTest code also uses a different code style (Google C++ style instead of LLVM style). Shall I reformat the entire GoogleTest code base?

I think we should just use the upstream style.

https://github.com/llvm/llvm-project/pull/65823