Add webpack `optimization.runtimeChunk` as a configurable setting (#13818)

GitOrigin-RevId: c50a149e77f9d05684de687fb730f3e290fa090e

services/web/webpack.config.dev.js

@@ -91,4 +91,8 @@ module.exports = merge(base, {
     preset: 'minimal',
     colors: true,
   },
+
+  optimization: {
+    runtimeChunk: process.env.WEBPACK_RUNTIME_CHUNK || false,
+  },
 })