Fix missing import

Author: parthmannan

megatron/core/utils.py

@@ -46,6 +46,7 @@
 from megatron.core import config
 from megatron.core._rank_utils import log_single_rank
 from megatron.core.package_info import __version__ as mcore_version
+from megatron.core.packed_seq_params import PackedSeqParams
 
 try:
     from torch.distributed._tensor import DTensor