docs: remove fibers dependency recommendation (#1966)

Author: jtlindsey

content/en/docs/5.configuration-glossary/5.configuration-css.md

@@ -15,17 +15,13 @@ In case you want to use `sass` make sure that you have installed `sass` and `sas
 
 ::code-group
 ```sh [Yarn]
-yarn add --dev sass sass-loader@10 fibers
+yarn add --dev sass sass-loader@10
 ```
 ```sh [NPM]
-npm install --save-dev sass sass-loader@10 fibers
+npm install --save-dev sass sass-loader@10
 ```
 ::
 
-::alert{type="info"}
-Synchronous compilation with `sass` (2x speed increase) [is enabled automatically](https://github.com/webpack-contrib/sass-loader) when `fibers` is installed.
-::
-
 - Type: `Array`
   - Items: `string`