[llvm] [mlir] [CMake] Do not set CMP0116 explicitly to old (PR #90385)

[Brad King via llvm-commits]

bradking wrote:

I suggest

```cmake
if(CMAKE_HOST_WIN32 AND CMAKE_VERSION VERSION_LESS 3.30)
  # Avoid CMP0116 depfile parsing bug on Windows paths:
  # https://gitlab.kitware.com/cmake/cmake/-/issues/25943
  cmake_policy(SET CMP0116 OLD)
endif()
```


https://github.com/llvm/llvm-project/pull/90385