[FEA]: Remove all raw `cudaMalloc`, `cudaHostMalloc`, `cudaFree`, etc calls in CUB catch2 tests with c2h vectors.

### Is this a duplicate?

- [X] I confirmed there appear to be no [duplicate issues](https://github.com/NVIDIA/cccl/issues) for this request and that I agree to the [Code of Conduct](CODE_OF_CONDUCT.md)

### Area

CUB

### Is your feature request related to a problem? Please describe.

I've encountered a number of memory leaks in CUB's tests stemming from the use of `cudaMalloc`, `cudaHostMalloc` etc with missing frees.

### Describe the solution you'd like

RAII containers, ideally `c2h` vectors, should be used instead. If needed, new ones like `c2h:::pinned_vector` should be added.

### Describe alternatives you've considered

_No response_

### Additional context

_No response_