[libomptarget] Drop remote plugin cmake version requirement to match llvm

LLVM docs at https://llvm.org/docs/CMake.html#quick-start state 3.13.4

Reviewed By: atmnpatel

Differential Revision: https://reviews.llvm.org/D113271

GitOrigin-RevId: 4f4c826e756b84cf494ff570b6ba048b37e11713
1 file changed