OpenAiChatOptions.Builder doesn't extend ChatOptionsBuilder, like OpenAiChatOptions extends ChatOptions

[michaelsembwever]

This can make code using a delegator pattern clumsy.

End-user example is in this commit:
datastax/ai-agent-java@78bdddd

I don't want to bind any of my classes unnecessarily to OpenAi* specifics,
so i am left having to <T extends Object> because there's no shared interface.

What would be nicer here is to <T extends ChatOptionsBuilder>.