Fix issue #244

[isaac-j-miller]

• Don't dispose the client websocket in the AsyncWebsocketMessageEnumerator
• Bump version suffix to beta.2 (not sure if this is correct)

[isaac-j-miller]

Fixes #261

[jsquire]

Hi @isaac-j-miller. Thank you for your contribution and your interest in improving the OpenAI developer experience. I apologize that it took so long for someone to review this.

After looking over the associated issue and the RealtimeSession implementation, the session also manages the socket lifetime in its Dispose method, so we agree that transferring ownership to the enumerator is a mistake.

Unfortunately, the structure of the repo has changed because it took us so long to get to this, so it can't be merged as-is. Since #527 is open to make other changes in this area, I adopted the proposed change there. I'm going to close this out.

Thank you, again, for your efforts in putting this together!