[PyTorch] Remove unnecessary dispatcher.h include in op_registration.h (#50315)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/50315
It's unused.
ghstack-source-id: 119798801
Test Plan: CI
Reviewed By: ezyang
Differential Revision: D25858937
fbshipit-source-id: fe4fdb33c1a443fdd17644c3f7f34c897abf383f
