Fix duplicate call to save_checkpoint when using deepspeed (#14946)
* Fix duplicate call to save_checkpoint when using deepspeed / stage3_gather_fp16_weights_on_model_save
* Revert "Fix duplicate call to save_checkpoint when using deepspeed / stage3_gather_fp16_weights_on_model_save"
This reverts commit 6a3dec0397723a8417351dc38fdebf14ab17756c.
* Delete correct duplicate invocation of deepspeed save_checkpoint