Remove torchelastic circleci configs (since torchelastic has been upstreamed to pytorch and tsm to torchx)

Summary: All the code in https://github.com/pytorch/elastic have either been upstreamed to https://github.com/pytorch/pytorch or https://github.com/pytorch/torchx. Removing unnecessary CI actions since they test nothing and are useless but get kicked off and fail 100% of the time.

Reviewed By: d4l3k

Differential Revision: D29919766

fbshipit-source-id: 556fff83a8bd97a25359854c5fc4364f53d689bf

Author: Kiuk Chung