[llvm] [libc] add multi-platform pre-commit github actions (PR #119104)

[Schrodinger ZHU Yifan via llvm-commits]

SchrodingerZhu wrote:

I can see that the cache writing run into errors but I don't know why. Perhaps github forbids some writes when update the cache too frequently. For the time being, I guess this is already the best caching effort I can do with sccache.

https://github.com/llvm/llvm-project/pull/119104