Move some code since it'll only run during ssr so it can be removed i…

…n the browser

next-packages/utils/src/index.js

@@ -41,15 +41,15 @@ export const insertStyles = (
 
     if (shouldSerializeToReactTree) {
       context.inserted[insertable.name] = rules.join('')
+      if (context.compat === undefined) {
+        return context.inserted[insertable.name]
+      }
     } else {
       rules.forEach(rule => {
         context.sheet.insert(rule)
       })
       context.inserted[insertable.name] = true
     }
-    if (context.compat === undefined) {
-      return context.inserted[insertable.name]
-    }
   }
 }