This ensures we use the `defaultLocale` for a locale domain when rendering non-static pages. Static pages will initially contain the global `defaultLocale` and then be updated on the client since we don't currently prerender a version of the pages for each locale domain.
Closes: https://github.com/vercel/next.js/issues/18970
This makes sure we don't incorrectly strip locale characters from the path if it is not a locale prefix e.g. `/fr` should not be removed from `/frank`. Additional tests have been added to ensure this isn't stripped for this case.
Fixes: https://github.com/vercel/next.js/issues/18332