support for langchain ChatOpenAI

[ranzhang]

with this class, we get: InternalServerError: Error code: 500 - 'Stream' object has no attribute 'model_dump'

Need an option to disable stream_runnable within crewai agent, to achieve something similar as:

agent_executor = AgentExecutor( agent=agent, tools=tools, memory=memory, verbose=True, stream_runnable=False )