setup: Dataclasses only when < 3.7 (#45844)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/45844
Someone pointed out that dataclasses were actually added to the python
stdlib in 3.7 and not 3.8, so bumping down the dependency on dataclasses
from 3.8 -> 3.7 makes sense here
Signed-off-by: Eli Uriegas <eliuriegas@fb.com>
Test Plan: Imported from OSS
Reviewed By: walterddr, malfet
Differential Revision: D24113367
Pulled By: seemethere
fbshipit-source-id: 03d2d93f7d966d48a30a8e2545fd07dfe63b4fb3
