fix: remove package reference

Author: stevapple

packages/vuepress-theme-reco/index.js

@@ -20,7 +20,6 @@ module.exports = (options, ctx) => ({
 
   plugins: [
     '@vuepress-reco/back-to-top',
-    '@vuepress-reco/extract-code',
     '@vuepress-reco/loading-page',
     '@vuepress-reco/pagation',
     '@vuepress-reco/comments',