use PreTrainedPipeline in custom handler

pipeline.py

@@ -2,7 +2,7 @@ import torch
 import transformers
 from typing import Dict, List, Any
 
-class EndpointHandler():
+class PreTrainedPipeline():
     def __init__(self, path="oleksandrfluxon/mpt-7b-chat-4bit"):
         print("===> path", path)
         config = transformers.AutoConfig.from_pretrained(path, trust_remote_code=True)