Migrate to training IR in executorch tests (#5941)

Summary:
Pull Request resolved: https://github.com/pytorch/executorch/pull/5941

Pull Request resolved: https://github.com/pytorch/executorch/pull/5875

as title

also bump pytorch pin

clone of D63845664, this time does not export to a fork

Reviewed By: mergennachin, tugsbayasgalan

Differential Revision: D63994058

fbshipit-source-id: 9a616770607ea73c71465d2728406b35151f81f0