nit: custom agent pass kwargs (#12739)

llama-index-core/llama_index/core/agent/custom/simple.py

@@ -116,6 +116,7 @@ class CustomSimpleAgentWorker(BaseModel, BaseAgentWorker):
             llm=llm,
             callback_manager=callback_manager,
             verbose=verbose,
+            **kwargs,
         )
 
     @abstractmethod