Webpack: only use [chunkhash] and [contenthash] in production builds

https://webpack.js.org/guides/build-performance/#avoid-production-specific-tooling

webpack/shared.js

@@ -52,9 +52,9 @@ module.exports = {
   },
 
   output: {
-    filename: 'packs/js/[name]-[chunkhash].js',
-    chunkFilename: 'packs/js/[name]-[chunkhash].chunk.js',
-    hotUpdateChunkFilename: 'packs/js/[id]-[contenthash].hot-update.js',
+    filename: 'packs/js/[name].js',
+    chunkFilename: 'packs/js/[name].chunk.js',
+    hotUpdateChunkFilename: 'packs/js/[id].hot-update.js',
     path: output.path,
     publicPath: join(FE_SUBDIRECTORY, '/'),
   },