Remove _get_wrapped_func (#35621)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/35621
Python 2 has reached end-of-life and is no longer supported by PyTorch.
`func.__wrapped__` can be used directly in Python 3.
Test Plan: CI
Differential Revision: D20842875
Pulled By: dreiss
fbshipit-source-id: 26f71df12db6d5118c8f278b27d747d647d07900
