[JIT] Expose `__deepcopy__` on script::Object (#40068)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/40068
Test Plan: Imported from OSS
Differential Revision: D22058808
Pulled By: jamesr66a
fbshipit-source-id: d8593b047c553389caea085337305ee893dc6877
