fix error included by #3998 (#4201)

Co-authored-by: Sijun He <[email protected]>

Author: Yam0214

paddlenlp/transformers/ernie_m/configuration.py

@@ -14,6 +14,8 @@
 """ ERNIE-M model configuration"""
 from __future__ import annotations
 
+from typing import Dict
+
 from ..configuration_utils import PretrainedConfig
 
 __all__ = ["ERNIE_M_PRETRAINED_INIT_CONFIGURATION", "ErnieMConfig", "ERNIE_M_PRETRAINED_RESOURCE_FILES_MAP"]
@@ -142,6 +144,7 @@ class ErnieMConfig(PretrainedConfig):
         >>> configuration = model.config
         ```"""
     model_type = "ernie_m"
+    attribute_map: Dict[str, str] = {"num_classes": "num_labels", "dropout": "classifier_dropout"}
     pretrained_init_configuration = ERNIE_M_PRETRAINED_INIT_CONFIGURATION
 
     def __init__(