fix(deps): update dependency hexo-generator-index to v4

Author: renovate[bot]

package-lock.json

@@ -19,7 +19,7 @@
     "hexo-extract-inline-scripts": "0.0.3",
     "hexo-generator-archive": "2.0.0",
     "hexo-generator-category": "2.0.0",
-    "hexo-generator-index": "3.0.0",
+    "hexo-generator-index": "4.0.0",
     "hexo-generator-sitemap": "3.0.1",
     "hexo-generator-tag": "2.0.0",
     "hexo-image-cloudflare": "0.3.2",