[INFRA]: Evaluate RAPIDS CMake test infrastructure for CUB

Try routing CUB tests through RAPIDS CMake test infrastructure and verify the fit with the existing CUB test flow.

Adding RAPIDS references here on the intended CTest GPU resource scheduling flow.

Related RAPIDS references:
- [RAPIDS CMake repo](https://github.com/rapidsai/rapids-cmake)
- [GPU resource scheduling docs](https://github.com/rapidsai/rapids-cmake/blob/main/docs/hardware_resources_and_testing.rst)
- [Example usage](https://github.com/rapidsai/rapids-cmake/blob/main/testing/test/add-multi-jobs-single-gpu/CMakeLists.txt)
- [rapids_test_gpu_requirements](https://github.com/rapidsai/rapids-cmake/blob/main/rapids-cmake/test/gpu_requirements.cmake)
- [Runtime GPU binding wrapper](https://github.com/rapidsai/rapids-cmake/blob/main/rapids-cmake/test/detail/run_gpu_test.cmake)

Start by locating the existing CUB CTest and GPU test flow, then compare it with RAPIDS CMake's hardware resource scheduling documentation and the linked add-multi-jobs-single-gpu example. Determine whether routing CUB tests through that infrastructure fits the current flow, and verify the resulting GPU scheduling behavior with the relevant tests.

Written by the indexing model from the issue text.