chore(deps): update dependency @unhead/vue to v3

Author: renovate[bot]

docs/package.json

@@ -10,7 +10,7 @@
   "dependencies": {
     "@nuxt/scripts": "^1.0.0",
     "@nuxtjs/mdc": "^0.20.0",
-    "@unhead/vue": "^2.0.12",
+    "@unhead/vue": "^3.0.0",
     "better-sqlite3": "^12.1.0",
     "docus": "^5.4.4",
     "nuxt": "^4.0.1",