Update minimum supported Python version to 3.6.2 (#47314)
Summary:
As typing.NoReturn is used in the codebase
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47314
Reviewed By: seemethere
Differential Revision: D24712847
Pulled By: malfet
fbshipit-source-id: f0692d408316d630bc11f1ee881b695437fb47d4
