[jit] allow dict to be mixed between tracing and scripting (#39601)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/39601
Test Plan: Imported from OSS
Reviewed By: jamesr66a
Differential Revision: D22202689
Pulled By: wanchaol
fbshipit-source-id: 5271eb3d8fdcda3d730a085aa555b43c35d14876
