chore(deps): update devdependency postcss to v8.4.31 [security]

Author: renovate[bot]

nuxt/package-lock.json

@@ -42,7 +42,7 @@
     "husky": "8.0.1",
     "lint-staged": "13.0.3",
     "netlify-cli": "12.0.0",
-    "postcss": "8.4.16",
+    "postcss": "8.4.31",
     "postcss-html": "1.5.0",
     "stylelint": "14.13.0",
     "stylelint-config-prettier": "9.0.3",