[clang-tools-extra] [clang-tidy] Rename google-readability-casting to modernize-avoid-c-style-cast (PR #171058)

[via cfe-commits]

================

----------------
zeyi2 wrote:

IMO this file should be renamed to `AvoidCStyleCastCheck.h` to better align with the check name: `modernize-avoid-c-style-cast`, same as the `.cpp` and the related files.

https://github.com/llvm/llvm-project/pull/171058