Revert "Add sharding tests to multigpu-test.sh and fix custom operator decorator (#77825)"
This reverts commit 8d4c8df33a58dc5f905dfdcee1cd124a79aaf2d8.
Reverted https://github.com/pytorch/pytorch/pull/77825 on behalf of https://github.com/janeyx99 due to as it will break multigpu test reporting