build(deps): bump postcss from 8.4.21 to 8.4.31 in /website (#3147)

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>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

website/package-lock.json

@@ -11732,9 +11732,9 @@
       }
     },
     "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==",
       "funding": [
         {
           "type": "opencollective",
@@ -11743,10 +11743,14 @@
         {
           "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"
       },

website/yarn.lock

@@ -8668,7 +8668,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"nanoid@npm:^3.3.4":
+"nanoid@npm:^3.3.6":
   version: 3.3.6
   resolution: "nanoid@npm:3.3.6"
   bin:
@@ -9731,13 +9731,13 @@ __metadata:
   linkType: hard
 
 "postcss@npm:^8.3.11, postcss@npm:^8.4.14, postcss@npm:^8.4.17, postcss@npm:^8.4.19":
-  version: 8.4.21
-  resolution: "postcss@npm:8.4.21"
+  version: 8.4.31
+  resolution: "postcss@npm:8.4.31"
   dependencies:
-    nanoid: ^3.3.4
+    nanoid: ^3.3.6
     picocolors: ^1.0.0
     source-map-js: ^1.0.2
-  checksum: e39ac60ccd1542d4f9d93d894048aac0d686b3bb38e927d8386005718e6793dbbb46930f0a523fe382f1bbd843c6d980aaea791252bf5e176180e5a4336d9679
+  checksum: 1d8611341b073143ad90486fcdfeab49edd243377b1f51834dc4f6d028e82ce5190e4f11bb2633276864503654fb7cab28e67abdc0fbf9d1f88cad4a0ff0beea
   languageName: node
   linkType: hard