Fix crash when api_server loads a turbomind model (#1304)

* fix loading workspace model

* fix lint

* update

* update

lmdeploy/archs.py

@@ -1,4 +1,5 @@
 # Copyright (c) OpenMMLab. All rights reserved.
+import os
 from typing import Literal, Optional, Union
 
 from lmdeploy.serve.async_engine import AsyncEngine
@@ -100,6 +101,9 @@ def check_vl_llm(config: dict) -> bool:
 
 def get_task(model_path: str):
     """get pipeline type and pipeline class from model config."""
+    if os.path.exists(os.path.join(model_path, 'triton_models', 'weights')):
+        # workspace model
+        return 'llm', AsyncEngine
     config = get_hf_config_content(model_path)
     if check_vl_llm(config):
         return 'vlm', VLAsyncEngine