Remove test on FakeProgram reducing size (#6178)

Summary:
Pull Request resolved: https://github.com/pytorch/executorch/pull/6178

Original exported_program outputs an OrderedDict, but now it just outputs an regular python dict. The size does not gets smaller anymore.

Reviewed By: lucylq

Differential Revision: D64260573

fbshipit-source-id: dc838026c189793e38baf26dae33a0aa4202efe6