fix(init): update old models

Author: ionmincu

src/uipath_langchain/_cli/_templates/main.py.template

@@ -1,9 +1,9 @@
 from langchain_core.messages import HumanMessage, SystemMessage
 from langgraph.graph import START, StateGraph, END
-from uipath_langchain.chat import UiPathChat
+from uipath_langchain.chat import UiPathChatOpenAI
 from pydantic import BaseModel
 
-llm = UiPathChat(model="gpt-4o-mini-2024-07-18")
+llm = UiPathChatOpenAI(use_responses_api=True)
 
 
 class GraphState(BaseModel):