Bump postcss from 8.4.24 to 8.4.31 in /src/Umbraco.Web.UI.Client (#14920)

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.24 to 8.4.31.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/8.4.24...8.4.31)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: direct:development
...

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src/Umbraco.Web.UI.Client/package-lock.json

@@ -78,7 +78,7 @@
         "less": "4.1.3",
         "lodash": "4.17.21",
         "merge-stream": "2.0.0",
-        "postcss": "8.4.24",
+        "postcss": "8.4.31",
         "run-sequence": "2.2.1"
       },
       "engines": {
@@ -13552,9 +13552,9 @@
       }
     },
     "node_modules/postcss": {
-      "version": "8.4.24",
-      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.24.tgz",
-      "integrity": "sha512-M0RzbcI0sO/XJNucsGjvWU9ERWxb/ytp1w6dKtxTKgixdtQDq4rmx/g8W1hnaheq9jgwL/oyEdH5Bc4WwJKMqg==",
+      "version": "8.4.31",
+      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.31.tgz",
+      "integrity": "sha512-PS08Iboia9mts/2ygV3eLpY5ghnUcfLV/EXTOW1E2qYxJKGGBUtNjN76FYHnMs36RmARn41bC0AZmn+rR0OVpQ==",
       "dev": true,
       "funding": [
         {

src/Umbraco.Web.UI.Client/package.json

@@ -90,7 +90,7 @@
     "less": "4.1.3",
     "lodash": "4.17.21",
     "merge-stream": "2.0.0",
-    "postcss": "8.4.24",
+    "postcss": "8.4.31",
     "run-sequence": "2.2.1"
   }
 }