Bump postcss from 8.4.14 to 8.4.20

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.14 to 8.4.20.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.14...8.4.20)

---
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": "^28.1.2",
-    "postcss": "^8.4.14",
+    "postcss": "^8.4.20",
     "postcss-cli": "^10.0.0",
     "postcss-loader": "^7.0.2",
     "remove": "^0.1.5",

yarn.lock

@@ -9400,7 +9400,7 @@ __metadata:
     jest-environment-jsdom: ^28.1.2
     monaco-editor: ^0.33.0
     monaco-editor-webpack-plugin: ^7.0.1
-    postcss: ^8.4.14
+    postcss: ^8.4.20
     postcss-cli: ^10.0.0
     postcss-loader: ^7.0.2
     process: ^0.11.10
@@ -10004,14 +10004,14 @@ __metadata:
   languageName: node
   linkType: hard
 
-"postcss@npm:^8.4.14":
-  version: 8.4.14
-  resolution: "postcss@npm:8.4.14"
+"postcss@npm:^8.4.20":
+  version: 8.4.20
+  resolution: "postcss@npm:8.4.20"
   dependencies:
     nanoid: ^3.3.4
     picocolors: ^1.0.0
     source-map-js: ^1.0.2
-  checksum: fe58766ff32e4becf65a7d57678995cfd239df6deed2fe0557f038b47c94e4132e7e5f68b5aa820c13adfec32e523b693efaeb65798efb995ce49ccd83953816
+  checksum: 1a5609ea1c1b204f9c2974a0019ae9eef2d99bf645c2c9aac675166c4cb1005be7b5e2ba196160bc771f5d9ac896ed883f236f888c891e835e59d28fff6651aa
   languageName: node
   linkType: hard