Bump postcss from 8.4.21 to 8.4.31

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.21 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/8.4.21...8.4.31)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

package-lock.json

@@ -6747,9 +6747,9 @@
             }
         },
         "node_modules/postcss": {
-            "version": "8.4.21",
-            "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.21.tgz",
-            "integrity": "sha512-tP7u/Sn/dVxK2NnruI4H9BG+x+Wxz6oeZ1cJ8P6G/PZY0IKk4k/63TDsQf2kQq3+qoJeLm2kIBUNlZe3zgb4Zg==",
+            "version": "8.4.31",
+            "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.31.tgz",
+            "integrity": "sha512-PS08Iboia9mts/2ygV3eLpY5ghnUcfLV/EXTOW1E2qYxJKGGBUtNjN76FYHnMs36RmARn41bC0AZmn+rR0OVpQ==",
             "dev": true,
             "funding": [
                 {
@@ -6759,10 +6759,14 @@
                 {
                     "type": "tidelift",
                     "url": "https://tidelift.com/funding/github/npm/postcss"
+                },
+                {
+                    "type": "github",
+                    "url": "https://github.com/sponsors/ai"
                 }
             ],
             "dependencies": {
-                "nanoid": "^3.3.4",
+                "nanoid": "^3.3.6",
                 "picocolors": "^1.0.0",
                 "source-map-js": "^1.0.2"
             },