Apply isort and black reformatting

Signed-off-by: Victarry <[email protected]>

nemo/core/optim/optimizer_with_main_params.py

@@ -30,9 +30,9 @@
 
 try:
     from megatron.core.parallel_state import (
-        get_expert_data_parallel_group,
         get_data_parallel_group,
         get_data_parallel_world_size,
+        get_expert_data_parallel_group,
     )
     from megatron.core.tensor_parallel import copy_tensor_model_parallel_attributes