DeepSpeed

7f3e82fe - do allgather only in shared optimizer states groups (#4167)

do allgather only in shared optimizer states groups (#4167) * skip all-gather * add notes --------- Co-authored-by: Logan Adams <114770087+loadams@users.noreply.github.com> Co-authored-by: Olatunji Ruwase <olruwase@microsoft.com>