Merge topic 'cuda-toolkit-vs' into release-3.18

a0280801f4 CUDA: Fix CMAKE_CUDA_COMPILER_TOOLKIT_ROOT detection in Visual Studio
90be0916b5 CUDA: Re-order some logic for determining the compiler
4ab5f109f0 CUDA: Remove unused variables while determining compiler
492e5f01fa CUDA: Simplify CMAKE_CUDA_COMPILER_TOOLKIT_ROOT computation
4785bd6153 CUDA: Skip the entire search for nvcc when it is CMAKE_CUDA_COMPILER

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !4921