Update ProcessGroupRoundRobin (#91172)
Summary:
Temporary fix to unblock jobs in https://fb.workplace.com/groups/300451907202972/permalink/906337097050850/
Real fix would be to remove use of _round_robin_process_group API and update corresponding references (e.g. PyText)
Test Plan: sandcastle
Differential Revision: D42169592
Pull Request resolved: https://github.com/pytorch/pytorch/pull/91172
Approved by: https://github.com/awgu
