Cleanup async execution for python RPC calls. (#53230)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53230
As part of https://github.com/pytorch/pytorch/issues/39351, cleaning
up the python call async execution.
ghstack-source-id: 123120119
Test Plan: waitforbuildbot
Reviewed By: rohan-varma
Differential Revision: D26800758
fbshipit-source-id: 50fe94c684bf53b907762e8bf196a6f6b97e4cf0
