[jit] Remove _assert_int_or_pair op (#34509)
Summary:
This one doesn't actually do anything so we don't need an op for it.
It is used inside `torch.nn.functional.unfold` which is already tested
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34509
Pulled By: driazati
Differential Revision: D20676445
fbshipit-source-id: b72d1308bdec593367ec4e14bf9a901d0b62e1cc
