fix NODE_ENV

.github/workflows/deploy-to-gh-pages.yml

@@ -23,7 +23,7 @@ jobs:
           npm run pre-build
           npm run build-ci
         env:
-          NODE_ENV: production
+          LESSON_BUILDER_ENV: production
 
       - name: Deploy 📦
         uses: JamesIves/github-pages-deploy-action@3.6.2