[llvm] [libc++] Shuffle the order of pre-commit CI jobs a bit (PR #128008)

[Nikolas Klauser via llvm-commits]

philnik777 wrote:

FWIW I find the title of the patch a bit misleading. This makes the pipeline even longer, which isn't at all obvious and I'm really not a huge fan of making it even longer. Is this intended to be permanent?

https://github.com/llvm/llvm-project/pull/128008