Update backtesting.mdx

docs/evaluation/tutorials/backtesting.mdx

@@ -226,7 +226,6 @@ gpt_4o = ChatOpenAI(model="gpt-4o")
 new_agent = create_react_agent(gpt_4o, tools=tools, state_modifier=modifier)
 
 def new_target(inputs):
-    rate_limiter.acquire()
     raw = new_agent.invoke(inputs)
     return {"messages": convert_to_openai_messages(raw['messages'])}
 
@@ -255,4 +254,4 @@ which GPT-4o is better than GPT-3.5:
 This was a simple example to show how you could backtest your production system against a new system.
 There are many different ways to do this backtesting, including using targeted filters
 to select the production runs you want to improve on, or using human preference
-data instead of evlautors defined in code.
+data instead of evlautors defined in code.