Sync webpack.conf.js from starterkit

The CssMinimizerOptions where for a patternfly issue which is already
resolved. patternfly/patternfly-react#5650

webpack.config.js

@@ -8,8 +8,6 @@ const CompressionPlugin = require("compression-webpack-plugin");
 const ESLintPlugin = require('eslint-webpack-plugin');
 const CockpitPoPlugin = require("./src/lib/cockpit-po-plugin");
 
-const webpack = require("webpack");
-
 // absolute path disables recursive module resolution, so build a relative one
 const nodedir = path.relative(process.cwd(), path.resolve((process.env.SRCDIR || __dirname), "node_modules"));
 
@@ -25,10 +23,7 @@ const copy_files = [
 const plugins = [
     new copy({ patterns: copy_files }),
     new extract({filename: "[name].css"}),
-    new ESLintPlugin({
-        extensions: ["js", "jsx"],
-        failOnWarning: true,
-    }),
+    new ESLintPlugin({ extensions: ["js", "jsx"] }),
     new CockpitPoPlugin(),
 ];
 
@@ -81,11 +76,7 @@ module.exports = {
                     },
                 },
             }),
-            new CssMinimizerPlugin({
-                minimizerOptions: {
-                    preset: ['default', { mergeLonghand: false }]
-                }
-            })
+            new CssMinimizerPlugin()
         ],
     },