.circleci: Add workflows for Python 3.8 (#31948)
Summary:
Done by just editing `.circleci/cimodel/data/dimensions.py` to include `3.8` and then regenerated using `.circleci/regenerate.sh`
cc kostmo, mingbowan, ezyang, soumith
Signed-off-by: Eli Uriegas <eliuriegas@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/31948
Differential Revision: D19602069
Pulled By: seemethere
fbshipit-source-id: ac57fde9d0c491c7d948a3f5944c3cb324d403c0
