Prepare 2.2.0-beta.1 release (Part 1)

[joseharriaga]

Features added

• Chat completion now supports audio input and output!
  • To configure a chat completion to request audio output using the gpt-4o-audio-preview model, use ChatResponseModalities.Text | ChatResponseModalities.Audio as the value for ChatCompletionOptions.ResponseModalities and create a ChatAudioOptions instance for ChatCompletionOptions.AudioOptions.
  • Input chat audio is provided to UserChatMessage instances using ChatContentPart.CreateInputAudioPart()
  • Output chat audio is provided on the OutputAudio property of ChatCompletion
  • References to prior assistant audio are provided via OutputAudioReference instances on the AudioReference property of AssistantChatMessage; AssistantChatMessage(chatCompletion) will automatically handle this, too
  • For more information, see the example in the README
• Predicted output can be used with chat completion: the new OutputPrediction property on ChatCompletionOptions can be populated with ChatMessageContentPart instances via ChatOutputPrediction.CreateStaticContentPrediction() to substantially accelerate some varieties of requests.
• For o3-mini, o1, and later models with reasoning capabilities:
  • The new DeveloperChatMessage, which replaces SystemChatMessage, can be used to provide instructions to the model
  • ChatCompletionOptions can specify a ReasoningEffortLevel property to adjust the level of token consumption the model will attempt to apply

[Experimental] Breaking changes

• The IDictionary<string, string> Metadata property in several request options types in the Assistants and RealtimeConversation areas have had their setters removed, aligning them with other request use of collections. The dictionaries remain writeable and use both initializer syntax and range copies to produce the same effect.