chore(deps-dev): bump postcss from 8.3.11 to 8.4.31

Bumps [postcss](https://github.com/postcss/postcss) from 8.3.11 to 8.4.31.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.3.11...8.4.31)

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

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

docs/package.json

@@ -40,7 +40,7 @@
     "imagemin-optipng": "8.0.0",
     "next-compose-plugins": "2.2.1",
     "next-optimized-images": "2.6.2",
-    "postcss": "8.3.11",
+    "postcss": "8.4.31",
     "postcss-color-converter": "1.0.4",
     "postcss-color-hsl": "2.0.0",
     "postcss-color-mod-function": "3.0.3",

yarn.lock

@@ -7426,7 +7426,7 @@ __metadata:
     next: 12.1.0
     next-compose-plugins: 2.2.1
     next-optimized-images: 2.6.2
-    postcss: 8.3.11
+    postcss: 8.4.31
     postcss-color-converter: 1.0.4
     postcss-color-hsl: 2.0.0
     postcss-color-mod-function: 3.0.3
@@ -13642,6 +13642,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"nanoid@npm:^3.3.6":
+  version: 3.3.6
+  resolution: "nanoid@npm:3.3.6"
+  bin:
+    nanoid: bin/nanoid.cjs
+  checksum: 7d0eda657002738aa5206107bd0580aead6c95c460ef1bdd0b1a87a9c7ae6277ac2e9b945306aaa5b32c6dcb7feaf462d0f552e7f8b5718abfc6ead5c94a71b3
+  languageName: node
+  linkType: hard
+
 "nanomatch@npm:^1.2.9":
   version: 1.2.13
   resolution: "nanomatch@npm:1.2.13"
@@ -16162,14 +16171,14 @@ __metadata:
   languageName: node
   linkType: hard
 
-"postcss@npm:8.3.11":
-  version: 8.3.11
-  resolution: "postcss@npm:8.3.11"
+"postcss@npm:8.4.31":
+  version: 8.4.31
+  resolution: "postcss@npm:8.4.31"
   dependencies:
-    nanoid: ^3.1.30
+    nanoid: ^3.3.6
     picocolors: ^1.0.0
-    source-map-js: ^0.6.2
-  checksum: 1a230553d74c66aa9585c90781ed8ea75f19cefea405d2117b67fbeb24b5b5e0e17be2e0c5a07db31dd085643a13394127ab2222e940771b70498331bf20f35e
+    source-map-js: ^1.0.2
+  checksum: 1d8611341b073143ad90486fcdfeab49edd243377b1f51834dc4f6d028e82ce5190e4f11bb2633276864503654fb7cab28e67abdc0fbf9d1f88cad4a0ff0beea
   languageName: node
   linkType: hard