[PyTorch] Run test_transformerencoderlayer on CUDA
Pull Request resolved: https://github.com/pytorch/pytorch/pull/75346
Preparing to add native fast path; need to test on CUDA!
Differential Revision: [D35327731](https://our.internmc.facebook.com/intern/diff/D35327731/)
Approved by: https://github.com/ngimel
