Remove parallel tool calls parameter

tools.py

@@ -50,7 +50,7 @@ llm = ChatHuggingFace(llm = HuggingFaceEndpoint(
                 endpoint_url="https://api-inference.huggingface.co/models/meta-llama/llama-2-7b-chat-hf",
                 temperature=0))
 tools = [add, subtract, divide, web_search]
-llm_with_tools = llm.bind_tools(tools, parallel_tool_calls = False)
+llm_with_tools = llm.bind_tools(tools)
 
 def retriever(state: AgentState) -> Dict:
     """