Clean up unused model instantiation (#65487)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/65487
Test Plan: Imported from OSS
Reviewed By: jingsh
Differential Revision: D31410880
Pulled By: b-koopman
fbshipit-source-id: 09b2d2d899a232e7334c82f00eff0f900e817853
