[FX] Fix GraphModule deepcopy to use deepcopied graph (#63090)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/63090
Test Plan: Imported from OSS
Reviewed By: ansley
Differential Revision: D30252471
Pulled By: jamesr66a
fbshipit-source-id: cafd7d7917935a5ea6ffa2a7fe9e9b2a9578b3e3
