Allow React 19 in peer deps

[david-crespo]

Just changing the peer deps might be insufficient. We might need to bump stuff like @headlessui/react.

[david-crespo]

I tested the canary on the marketing site, which is on React 18, to make sure it doesn't only work with React 19. It all seemed to work fine.

[david-crespo]

This is the only major bump, so it's worth testing specifically. It's used in the Listbox, which is only used in one spot: the marketing site events page. It works fine.

https://github.com/search?q=org%3Aoxidecomputer+design-system+listbox+NOT+repo%3Aoxidecomputer%2Fconsole&type=code

https://github.com/oxidecomputer/oxide-computer/blob/f83e368dc899e9cca6bb1cf168c72befc153dbce/app/routes/events.tsx#L64-L70

[benjaminleonard]

🚀 PR was released in v2.2.2 🚀