When updating assistants do not return information not updated

[CakeCrusher]

Observe this test:

@pytest.mark.dependency(
    depends=["test_create_message_in_thread", "test_get_messages_in_thread"]
)
def test_modify_message_in_thread(openai_client: OpenAI, thread_id: str):
    # Create a message in the thread for testing
    message_data = {
        "role": "user",
        "content": "Initial message content",
    }
    message_response = openai_client.beta.threads.messages.create(
        thread_id=thread_id, **message_data
    )
    message_id = message_response.id

    retrieved_message = openai_client.beta.threads.messages.retrieve(
        thread_id=thread_id, message_id=message_id
    )

    assert retrieved_message.id == message_id
    assert retrieved_message.thread_id == thread_id
    assert retrieved_message.role == message_data["role"]
    assert retrieved_message.content[0].text.value == message_data["content"]
    assert retrieved_message.attachments == []
    assert retrieved_message.metadata == {}

    # Data for modification
    updated_metadata = {"modified": "true", "user": "abc123"}

    # Modify the message
    modified_message = openai_client.beta.threads.messages.update(
        thread_id=thread_id,
        message_id=message_id,
        metadata=updated_metadata,
    )

    assert modified_message.id == message_id
    assert modified_message.thread_id == thread_id
    assert modified_message.role == message_data["role"]
    assert modified_message.content[0].text.value == message_data["content"]
    assert modified_message.attachments == None
    assert modified_message.metadata == updated_metadata

    retrieved_updated_message = openai_client.beta.threads.messages.retrieve(
        thread_id=thread_id, message_id=message_id
    )

    # Verify the response
    assert retrieved_updated_message.id == message_id
    assert retrieved_updated_message.thread_id == thread_id
    assert retrieved_updated_message.role == message_data["role"]
    assert (
        retrieved_updated_message.content[0].text.value
        == message_data["content"]
    )
    assert retrieved_updated_message.attachments == []
    assert retrieved_updated_message.metadata == updated_metadata