This is a follow-up to https://github.com/vercel/next.js/pull/16973 which adds handling for the breaking change in the latest version of css-loader that causes unresolved file references in `url` or `import` to cause the build to fail. This fixes it by adding our own resolve checking and when it fails disabling the `css-loader`'s handling of it. 

Fixes: https://github.com/vercel/next.js/issues/17701