Revert D25254920: [pytorch][PR] Add type annotations to torch.onnx.* modules
Test Plan: revert-hammer
Differential Revision:
D25254920 (https://github.com/pytorch/pytorch/commit/40a2dd7e1eccdcf756fec92084a54eeb397f75cd)
Original commit changeset: dc9dc036da43
fbshipit-source-id: c17cb282ebf90ecbae4023aa63ecbb443a87037d
