[clang-tools-extra] [clang-tidy][NFC] Remove regex hacks to match full lines in tests (PR #162293)

[Carlos Galvez via cfe-commits]

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

LGTM, obviously I haven't done a very exhausting reviewing but I haven't spotted anything strange.

Perhaps splitting one patch per clang-tidy module would have been reasonable, but I'm fine reviewing it as one patch too.

https://github.com/llvm/llvm-project/pull/162293