Cleanup since FEATURE_TORCH_MOBILE is always true. (#55835)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55835
Now that https://github.com/pytorch/pytorch/pull/55238 is landed for a
week and no complains. It seems safe to say FEATURE_TORCH_MOBILE is
always true and we can do some cleanup.
Test Plan: Imported from OSS
Reviewed By: ezyang, walterddr
Differential Revision: D27721284
Pulled By: ailzhang
fbshipit-source-id: 4896bc5f736373d0922cfbe8eed0d16df62f0fa1
