Bump postcss from 8.4.20 to 8.4.21

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.20 to 8.4.21.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.20...8.4.21)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

packages/playground/package.json

@@ -43,7 +43,7 @@
     "html-webpack-plugin": "^5.5.0",
     "jest": "^29.3.1",
     "jest-environment-jsdom": "^29.3.1",
-    "postcss": "^8.4.20",
+    "postcss": "^8.4.21",
     "postcss-cli": "^10.1.0",
     "postcss-loader": "^7.0.2",
     "remove": "^0.1.5",

yarn.lock

@@ -9584,7 +9584,7 @@ __metadata:
     jest-environment-jsdom: ^29.3.1
     monaco-editor: ^0.33.0
     monaco-editor-webpack-plugin: ^7.0.1
-    postcss: ^8.4.20
+    postcss: ^8.4.21
     postcss-cli: ^10.1.0
     postcss-loader: ^7.0.2
     process: ^0.11.10
@@ -10188,7 +10188,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"postcss@npm:^8.4.19, postcss@npm:^8.4.20":
+"postcss@npm:^8.4.19":
   version: 8.4.20
   resolution: "postcss@npm:8.4.20"
   dependencies:
@@ -10199,6 +10199,17 @@ __metadata:
   languageName: node
   linkType: hard
 
+"postcss@npm:^8.4.21":
+  version: 8.4.21
+  resolution: "postcss@npm:8.4.21"
+  dependencies:
+    nanoid: ^3.3.4
+    picocolors: ^1.0.0
+    source-map-js: ^1.0.2
+  checksum: e39ac60ccd1542d4f9d93d894048aac0d686b3bb38e927d8386005718e6793dbbb46930f0a523fe382f1bbd843c6d980aaea791252bf5e176180e5a4336d9679
+  languageName: node
+  linkType: hard
+
 "prelude-ls@npm:^1.2.1":
   version: 1.2.1
   resolution: "prelude-ls@npm:1.2.1"