Add the latest stable Gemini models

[KingXMAX]

The latest Gemini models have been finally released: Gemini 2.5 Pro (Not Preview anymore) Gemini 2.5 Flash (Finally Stable) Here is the docs page that contains all info you need to add the models successfully: https://ai.google.dev/gemini-api/docs/models Thank you.

[sceuick]

If you use Google AI provider, the model list will update automatically.