Fix GIL issue when acquiring multiple sessions. (#58584)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/58584
Test Plan: buck test //caffe2/torch/csrc/deploy:test_deploy
Reviewed By: wconstab
Differential Revision: D28545314
fbshipit-source-id: 45cb0e4d80d4766ec1aed6a51679af3424cb0878
