Faster builds: build-dev should only build nodejs version

webpack.dev.js

@@ -1,9 +1,9 @@
 const merge = require('webpack-merge');
 const prod_configs = require('./webpack.config.js');
 
-module.exports = prod_configs.map((config) =>
+module.exports = [
   merge.merge(prod_configs[0], {
     mode: 'development',
     devtool: 'inline-source-map',
-  })
-);
+  }),
+];