pytorch

baf8f4c0 - [19/n] [torch/elastic] Introduce _RendezvousKeepAliveOp (#57147)

[19/n] [torch/elastic] Introduce _RendezvousKeepAliveOp (#57147) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/57147 This PR introduces the `_RendezvousKeepAliveOp` type that represents a rendezvous keep-alive heartbeat operation to be executed via a `_RendezvousOpExecutor`. ghstack-source-id: 127685037 Test Plan: Run the existing and new unit tests. Reviewed By: tierex Differential Revision: D28059733 fbshipit-source-id: 31fd8fc06f03d8f9cd21558b15a06dea7ad85bc6