Fix python 3.9 builds on Windows (#47602)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/47460.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47602
Reviewed By: heitorschueroff
Differential Revision: D24832487
Pulled By: malfet
fbshipit-source-id: 8846caeac5e767e8066470d5c981218f147c88dc
