Add rapids_cuda_set_runtime to default includes of cuda

[robertmaynard]

Description

The rapids_cuda_set_runtime is now part of the functions you get when including rapids-cuda.cmake

Checklist

• [x] I am familiar with the Contributing Guidelines.
• [x] New or existing tests cover these changes.
• [x] The documentation is up to date with these changes.

[robertmaynard]

/merge