pytorch

988e31c7 - Revert D21752017: [pytorch][PR] Test PyTorch using python-3.8 + GCC-9 on Bionic

Revert D21752017: [pytorch][PR] Test PyTorch using python-3.8 + GCC-9 on Bionic Test Plan: revert-hammer Differential Revision: D21752017 Original commit changeset: 56c841636349 fbshipit-source-id: adf08e03ba9610050fc5440ef453789f805fdc6b