Part of #134054.
This corresponds to the pytorch mypy changes from D61493706. Updating takes so
long and touches so many files that it's impossible to land as a whole without conflicting with some other intermediate change.
So landing these 'type: ignore' for pytorch in advance of them actually being needed.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/134202
Approved by: https://github.com/Skylion007
Changed the API of `pipeline()` to take microbatch instead of full batch as example args.
Main purpose is to:
- make this API more atomic;
- decouple tracing frontend from runtime info like `num_chunks`.
Side effects:
- Creates opportunity for varying `num_chunks` of schedules with the same `pipe` object.
- User has to create example microbatch input.
- Chunk spec stuff are now all moved to runtime side.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/128163
Approved by: https://github.com/H-Huang
