fix(train): guard checkpoint dir ops with rank 0 to prevent DDP race condition#908

wadeKeith wants to merge 1 commit intoPhysical-Intelligence:mainPhysical-Intelligence/openpi:mainfrom

wadeKeith:fix/ddp-checkpoint-race-conditionwadeKeith/openpi-1:fix/ddp-checkpoint-race-conditionCopy head branch name to clipboard