fix(pt): typo in epoch training (#5410)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Bug Fixes**
* Fixed configuration lookup for the epoch count so training now reads
and respects the configured number of epochs.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: OutisLi

deepmd/pd/train/training.py

@@ -141,7 +141,7 @@ def __init__(
 
         # Iteration config
         self.num_steps = training_params.get("numb_steps")
-        self.num_epoch = training_params.get("num_epoch")
+        self.num_epoch = training_params.get("numb_epoch")
         self.num_epoch_dict = training_params.get("num_epoch_dict")
         self.acc_freq: int = training_params.get(
             "acc_freq", 1

deepmd/pt/train/training.py

@@ -164,7 +164,7 @@ def __init__(
 
         # Iteration config
         self.num_steps = training_params.get("numb_steps")
-        self.num_epoch = training_params.get("num_epoch")
+        self.num_epoch = training_params.get("numb_epoch")
         self.num_epoch_dict = training_params.get("num_epoch_dict")
         self.disp_file = training_params.get("disp_file", "lcurve.out")
         self.disp_freq = training_params.get("disp_freq", 1000)