Support AI SDK 6 (Stable)

[The-Best-Codes]

AI SDK v6 is officially released in stable, would love to see this package support it 🙌
https://vercel.com/blog/ai-sdk-6

[AviVahl]

there's an ongoing PR: #307

[bernaferrari]

Can you make so the new strict parameter enables required_parameters automatically and every required property so json never fails?