fix security issue #9 (#653)

fix https://github.com/yomorun/yomo/security/dependabot/9

Author: fanweixiao

docs/package.json

@@ -33,7 +33,7 @@
     "@types/node": "18.15.11",
     "autoprefixer": "^10.4.14",
     "next-sitemap": "^4.0.7",
-    "postcss": "^8.4.21",
+    "postcss": "^8.4.31",
     "tailwindcss": "^3.3.1",
     "typescript": "5.0.4"
   },