This picks up on the inlining work in https://github.com/vercel/next.js/pull/20598 to also include webpack loader inlining optimizations.
This includes:
* The dependencies of sass-loader
* resolve-url-loader
And for added benefit:
* babel-plugin-transform-define
* babel-plugin-transform-react-remove-prop-types
style-loader and css-loader didn't inline easily. Perhaps we can come back to these ones.
