Update dependency postcss to ^8.4.31

Author: renovate[bot]

package.json

@@ -18,7 +18,7 @@
     "autoprefixer": "^10.4.15",
     "nuxt": "^3.7.4",
     "nuxt-icon": "^0.5.0",
-    "postcss": "^8.4.30",
+    "postcss": "^8.4.31",
     "prettier": "^3.0.3",
     "tailwindcss": "^3.3.3"
   },