When working with an agent driven by the OpenAI Chat Client, I noticed that the client doesn't respect the setting allow_multiple_tool_calls from the agent.

This is where the client translates the chat options and it clearly omits the allow_multiple_tool_calls option: https://github.com/microsoft/agent-framework/blob/main/python/packages/core/agent_framework/openai/_chat_client.py#L159. It should be translated to parallel_tool_calls: https://platform.openai.com/docs/guides/function-calling#configuring-parallel-function-calling

We should have this fix ASAP.