Enable Python code coverage for onnx runs (#47387)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/44120
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47387
Reviewed By: heitorschueroff
Differential Revision: D24737378
Pulled By: janeyx99
fbshipit-source-id: 79e3d0b62f7da0617330f312fb1ed548c6be2a3b
