Modify the design

Author: flybird11111

colossalai/checkpoint_io/__init__.py

@@ -2,7 +2,6 @@
 from .general_checkpoint_io import GeneralCheckpointIO
 from .hybrid_parallel_checkpoint_io import HybridParallelCheckpointIO
 
-from .distributed_checkpoint_io import DistributedCheckpointIO
 from .index_file import CheckpointIndexFile
 from .moe_checkpoint import MoECheckpointIO
 
@@ -12,5 +11,4 @@
     "GeneralCheckpointIO",
     "HybridParallelCheckpointIO",
     "MoECheckpointIO",
-    "DistributedCheckpointIO",
 ]