Improves React 19 compatibility

• Improves React 19 compatibility for TypeScript users by changing @types/react from a direct dependency to a peer dependency in @sanity/types.

To initiate a new Sanity Studio project or upgrade an existing one, please refer to our comprehensive guide on Installing and Upgrading Sanity Studio.

If you are updating from a version earlier than 3.37.0, you should also check out this article to ensure your dependencies are up to date.