Revert [DDP] Support not all outputs used in loss calculation (#61497)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61497
Reverts [DDP] Support not all outputs used in loss calculation
ghstack-source-id: 133589153
Test Plan: CI, ping authors to run their workflow on this diff
Reviewed By: zhaojuanmao
Differential Revision: D29642892
fbshipit-source-id: 81a15b9ab3329602f34d3758bb0799005a053d4f
