[BE] Enable Ruff's Flake8 PYI034 (#111105)
Enable [non-self-return-type (PYI034)](https://docs.astral.sh/ruff/rules/non-self-return-type/#non-self-return-type-pyi034)
Link: #110950
**EDIT**: to newly added reviewers, please ignore the request, it's due to a rebase error :sweat_smile:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/111105
Approved by: https://github.com/Skylion007
