Make it difficult for researchers to load legacy "CUDA" modules.

There are two legacy "CUDA" modules on Cheaha. I would like for us to make it as difficult for researchers to see or manually load either of these modules as possible (or make it impossible, if we can do that). I believe they are necessary for loading cuDNN versions, so they must remain on Cheaha for the time being.

CUDA/11.3.1-GCC-10.3.0
CUDA/11.4.1