[llvm] [libcxx][Github] Bump Runners to Next Group (PR #168122)

[Louis Dionne via llvm-commits]

ldionne wrote:

I think this is caused by some weird clang-tidy version mismatch happening because the new image is using a slightly more up-to-date incarnation of `clang-22`. Still looking into it, but I am able to reproduce it in a Docker image.

https://github.com/llvm/llvm-project/pull/168122