Source-map library update

[Robinfr]

I'm getting warnings from the source-map library that is being used. Webpack is throwing warnings like this:

./node_modules/css/node_modules/source-map/lib/source-map/source-node.js
8:45-52 Critical dependency: require function is used in a way in which dependencies cannot be statically extracted
 @ ./node_modules/css/node_modules/source-map/lib/source-map/source-node.js
 @ ./node_modules/css/node_modules/source-map/lib/source-map.js
 @ ./node_modules/css/lib/stringify/source-map-support.js
 @ ./node_modules/css/lib/stringify/index.js
 @ ./node_modules/css/index.js

I believe this would be fixed if the used source-map library is updated in package.json.

[holblin]

I worked on removing the source-map support. This will solve the issue. Trying to reach out to the rework members before going into the fork route (and discussing with my company for the PR route).
ref: #164