Issue #3307713 by lauriii, Spokje: Remove @ckeditor/ckeditor5-dev-utils

(cherry picked from commit d0154b5b)

core/modules/ckeditor5/webpack.config.js

 const path = require('path');
 const fs = require('fs');
 const webpack = require('webpack');
-const { styles, builds } = require('@ckeditor/ckeditor5-dev-utils');
 const TerserPlugin = require('terser-webpack-plugin');
 
 function getDirectories(srcpath) {

core/package.json

@@ -43,7 +43,6 @@
     "@ckeditor/ckeditor5-basic-styles": "~35.1.0",
     "@ckeditor/ckeditor5-block-quote": "~35.1.0",
     "@ckeditor/ckeditor5-code-block": "~35.1.0",
-    "@ckeditor/ckeditor5-dev-utils": "~30.4.0",
     "@ckeditor/ckeditor5-editor-classic": "~35.1.0",
     "@ckeditor/ckeditor5-editor-decoupled": "~35.1.0",
     "@ckeditor/ckeditor5-essentials": "~35.1.0",