[clang] [clang-format] Add common attribute macros to Google style (PR #76239)

[Ilya Biryukov via cfe-commits]

ilya-biryukov wrote:

This change did not aim to change the behavior, it's quite the opposite, I tried to guide `clang-format` parsing to recognize attribute and format the code in the way we always intended it to.

If there is a way to do that without adding the macro names to the configuration explicitly, it would definitely be preferable for us too. I just went with what I thought to be the easiest path as I don't really expect people to use the macro names for other purposes. Definitely not `ABSL_GUARDED_BY`, although I can see why `GUARDED_BY` might be more contentious.

https://github.com/llvm/llvm-project/pull/76239