Update pynvml to nvidia-ml-py (#2646)
Summary:
NVIDIA now provides `pynvml` through `nvidia-ml-py`, and gives noisy warnings to users of the old package.
Pull Request resolved: https://github.com/pytorch/benchmark/pull/2646
Reviewed By: xuzhao9
Differential Revision: D83498283
Pulled By: huydhn
fbshipit-source-id: 2c9993237dda9f539fc9a6711d8d1e7d741ab13f
