Update dependency postcss to ^8.4.31

Author: renovate[bot]

package.json

@@ -18,7 +18,7 @@
     "autoprefixer": "^10.4.16",
     "nuxt": "^3.8.0",
     "nuxt-icon": "^0.6.5",
-    "postcss": "^8.4.30",
+    "postcss": "^8.4.31",
     "prettier": "^3.0.3",
     "tailwindcss": "^3.3.3"
   },