Revert D30876591: [pytorch][PR] Pin scipy to 1.6.3 on Windows and Mac
Test Plan: revert-hammer
Differential Revision:
D30876591 (https://github.com/pytorch/pytorch/commit/39f2b9de2ac7fb14e4aaf61863e98d01a53bc875)
Original commit changeset: 4946e0922063
fbshipit-source-id: b8beff3d973b21fe09c158baef25344030f8fb08