fix: get-webpack-version.js

`require.main` is undefined while running WebStorm code assistance analyzer of `webpack.config.js`

Author: unkernet

lib/utils/get-webpack-version.js

@@ -1,4 +1,8 @@
 // eslint-disable-next-line import/no-extraneous-dependencies
+// require.main is undefined while running WebStorm code assistance analyzer of webpack.config.js
+if (!require.main) {
+  require.main = { require };
+}
 const webpackVersion = require.main.require('webpack/package.json').version;
 
 /**