[clang] [CMake]Fully delete the deprecated LLVM_USE_CRT* (PR #66850)

[Mike Hommey via cfe-commits]

glandium wrote:

> Which used to be MT and with this change is now MD.

(because our script was still using LLVM_USE_CRT_RELEASE)

https://github.com/llvm/llvm-project/pull/66850