Move inter-op settings into ATen/Parallel (#20050)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20050
ghimport-source-id: cc102bab8abf3e56c099245976786317ed63ea14
Differential Revision: D15248576
Pulled By: ilia-cher
fbshipit-source-id: 55ddcb7af387ddfc68a42ac7167de07ea648e249
