inductor(CPU): skip weight packing when autocast is enabled (#100844)
Currently, the packed op doesn't support autocast and the packing path happened before AOTAutograd, which changes the default autocast behavior. Now, we disable the packing path, and the bfloat16 packing path can work after we move this path after AOTAutograd(I will do it after https://github.com/pytorch/pytorch/pull/100652 is done).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/100844
Approved by: https://github.com/jgong5, https://github.com/jansel
