Remove sharding code from tests (#27818)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/27818
This has been turned off since january. Might as well clean it up. I want to do a bit of refactoring in this area.
ghstack-source-id: 91827750
Test Plan: sandcastle
Differential Revision: D17898077
fbshipit-source-id: e70bf8ee72b4703767d4e38f8c346a7849a866f5
