[llvm] [LLVM] Remove explicit dependency on builtins build (PR #159854)

[Michael Kruse via llvm-commits]

Meinersbur wrote:

I don't know the compiler-rt/builtins system well enough to know whether theses dependencies can jsut be removed. Would't it be more elegant to avoid `BUILD_ALWAYS` in the first place?

https://github.com/llvm/llvm-project/pull/159854