[llvm] [openmp] Deprecate LLVM_ENABLE_PROJECTS in favor of LLVM_ENABLE_RUNTIMES (PR #124711)

[Michael Kruse via llvm-commits]

Meinersbur wrote:

Adding the missing dependency in #130975. After that, I don't see any remaining issue for deprecating LLVM_ENABLE_PROJECTS=openmp.

https://github.com/llvm/llvm-project/pull/124711