Use `next/font` instead of hardcoded import from google fonts

[toto04]

references this comment

This has a couple of advantages:

• Allows Next to "optimize" (whatever they mean by that) font loading, letting it decide when and where to load a font.
• Allows us to not call Google's APIs at each page load, which is a plus on privacy, latency (hypothetically) and reliability (kinda).

Links:
https://nextjs.org/docs/app/api-reference/components/font