[clang-tools-extra] fix(clang-tools-extra/**.py): fix invalid escape sequences (PR #94028)

[Piotr Zegar via cfe-commits]

https://github.com/PiotrZSL approved this pull request.

LGTM,
I will merge this once I confirm that it still works.

https://github.com/llvm/llvm-project/pull/94028