make ProcessException pickleable (#70118)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/70116
Happy to add tests if you let me know the best place to put them.
cc VitalyFedyunin
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70118
Reviewed By: malfet
Differential Revision: D33255899
Pulled By: ejguan
fbshipit-source-id: 41d495374182eb28bb8bb421e890eca3bddc077b
