Revert D28645531: .github: Add Windows GPU workflow
Test Plan: revert-hammer
Differential Revision:
D28645531 (https://github.com/pytorch/pytorch/commit/51884c647965d704bd25150784729f8449459264)
Original commit changeset: 6ed1a2dead9c
fbshipit-source-id: e082d7d50de77d0572596111e95a3da3a350a319
