Accept `next/font/google` as well as `@next/font/google` (#3723)
Aligning with https://github.com/vercel/next.js/pull/45707, this allows users to import fonts from `next/font/google` as well as `@next/font/google`.
Test Plan: Adjusted tests to use `next/font/google` and added another test to verify `@next/font/google` continues to work.