[clang] [llvm] [OpenMP] Remove 'libomptarget.devicertl.a' fatbinary and use static library (PR #126143)

[Michael Kruse via llvm-commits]

Meinersbur wrote:

We already have a host-side `libomptarget`:
https://github.com/llvm/llvm-project/blob/cfd8980fe79872feb9ed81959aa018681c7b3354/offload/src/CMakeLists.txt#L9

https://github.com/llvm/llvm-project/pull/126143