Fix serialization of AutoResume (#9616)

* fix serialization of autoresume

* update undefined variables

nemo/lightning/resume.py

@@ -4,8 +4,10 @@
 import lightning_fabric as fl
 import pytorch_lightning as pl
 
+from nemo.lightning import io
 from nemo.utils import logging
 from nemo.utils.app_state import AppState
+from nemo.utils.model_utils import uninject_model_parallel_rank
 
 
 class Resume:
@@ -22,7 +24,7 @@ def setup(self, model, trainer: Union[pl.Trainer, fl.Fabric]):
             trainer.checkpoint_callback.last_model_path = ckpt_path
 
 
-class AutoResume(Resume):
+class AutoResume(Resume, io.IOMixin):
     """Class that handles the logic for setting checkpoint paths and restoring from
     checkpoints in NeMo.
     """
@@ -101,15 +103,15 @@ def nemo_path(self, model=None) -> Optional[Path]:
                     warn = f"There were no checkpoints found in checkpoint_dir or no checkpoint folder at checkpoint_dir :{checkpoint_dir}. "
                     if checkpoint is None:
                         warn += "Training from scratch."
-                    elif checkpoint == resume_from_checkpoint:
-                        warn += f"Training from {resume_from_checkpoint}."
+                    elif checkpoint == self.path:
+                        warn += f"Training from {self.path}."
                     logging.warning(warn)
                 else:
                     raise NotFoundError(
                         f"There were no checkpoints found in checkpoint_dir or no checkpoint folder at checkpoint_dir :{checkpoint_dir}. Cannot resume."
                     )
             elif len(end_checkpoints) > 0:
-                if resume_past_end:
+                if self.resume_past_end:
                     if len(end_checkpoints) > 1:
                         if 'mp_rank' in str(end_checkpoints[0]):
                             checkpoint = end_checkpoints[0]