Back out "Revert D25757721: [pytorch][PR] Run mypy on more test files" (#50142)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/50142
Original commit changeset: 58437d719285
Test Plan: OSS CI
Reviewed By: walterddr, ngimel
Differential Revision: D25803866
fbshipit-source-id: d6b83a5211e430c0451994391876103f1ad96315
