Teams with agents that contain duplicated produced_message_types result in an ValueError exception

[jorge-wonolo]

What happened?

Describe the bug
On 0.53.0 output_content_type for agents is automatically registered into the team Code Reference. When a team is comprised of agents that share the same output_content_type then a ValueError is raised.

To Reproduce
Add into a team 2 agents with the same Pydantic model as output_content_type.

ValueError: Message type <class 'autogen_agentchat.messages.StructuredMessage[<TestModel>]'> is already registered.

Expected behavior
Only register structured messages that have not been registered previously.

Screenshots
If applicable, add screenshots to help explain your problem.

Additional context
I have added #6354 for your consideration

Which packages was the bug in?

Python AgentChat (autogen-agentchat>=0.4.0)

AutoGen library version.

Python 0.5.3

Other library version.

No response

Model used

gpt-4o

Model provider

OpenAI

Other model provider

No response

Python version

3.11

.NET version

None

Operating system

MacOS