Update modernbert_preprocessor.py

Author: maitry63

keras_hub/src/models/modernbert/modernbert_preprocessor.py

@@ -2,7 +2,7 @@
 from keras import ops
 from keras_hub.src.models.preprocessor import Preprocessor
 from keras_hub.src.api_export import keras_hub_export
-from keras_hub.src.layers.modeling.packer import Packer
+from keras_hub.src.layers.preprocessing import start_end_packer
 
 @keras_hub_export("keras_hub.models.ModernBertPreprocessor")
 class ModernBertPreprocessor(Preprocessor):
@@ -27,7 +27,7 @@ def __init__(
     ):
         super().__init__(tokenizer=tokenizer, **kwargs)
 
-        self.packer = Packer(
+        self.packer = start_end_packer.StartEndPacker(
             start_token_id=tokenizer.cls_token_id,
             end_token_id=tokenizer.sep_token_id,
             pad_value=tokenizer.pad_token_id,
@@ -63,4 +63,4 @@ def get_config(self):
         config.update({
             "sequence_length": self.packer.sequence_length,
         })
-        return config
+        return config