Bump postcss from 8.4.23 to 8.4.33 in /playground

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.23 to 8.4.33.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.23...8.4.33)

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

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

playground/yarn.lock

@@ -1250,10 +1250,10 @@ ms@2.1.2:
   resolved "https://registry.yarnpkg.com/ms/-/ms-2.1.2.tgz#d09d1f357b443f493382a8eb3ccd183872ae6009"
   integrity sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==
 
-nanoid@^3.3.6:
-  version "3.3.6"
-  resolved "https://registry.yarnpkg.com/nanoid/-/nanoid-3.3.6.tgz#443380c856d6e9f9824267d960b4236ad583ea4c"
-  integrity sha512-BGcqMMJuToF7i1rt+2PWSNVnWIkGCU78jBG3RxO/bZlnZPK2Cmi2QaffxGO/2RvWi9sL+FAiRiXMgsyxQ1DIDA==
+nanoid@^3.3.7:
+  version "3.3.7"
+  resolved "https://registry.yarnpkg.com/nanoid/-/nanoid-3.3.7.tgz#d0c301a691bc8d54efa0a2226ccf3fe2fd656bd8"
+  integrity sha512-eSRppjcPIatRIMC1U6UngP8XFcz8MQWGQdt1MTBQ7NaAmvXDfvNxbvWV3x2y6CdEUciCSsDHDQZbhYaB8QEo2g==
 
 natural-compare-lite@^1.4.0:
   version "1.4.0"
@@ -1346,11 +1346,11 @@ picomatch@^2.0.4, picomatch@^2.2.1, picomatch@^2.3.1:
   integrity sha512-JU3teHTNjmE2VCGFzuY8EXzCDVwEqB2a8fsIvwaStHhAWJEeVd1o1QD80CU6+ZdEXXSLbSsuLwJjkCBWqRQUVA==
 
 postcss@^8.4.23:
-  version "8.4.23"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.23.tgz#df0aee9ac7c5e53e1075c24a3613496f9e6552ab"
-  integrity sha512-bQ3qMcpF6A/YjR55xtoTr0jGOlnPOKAIMdOWiv0EIT6HVPEaJiJB4NLljSbiHoC2RX7DN5Uvjtpbg1NPdwv1oA==
+  version "8.4.33"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.33.tgz#1378e859c9f69bf6f638b990a0212f43e2aaa742"
+  integrity sha512-Kkpbhhdjw2qQs2O2DGX+8m5OVqEcbB9HRBvuYM9pgrjEFUg30A9LmXNlTAUj4S9kgtGyrMbTzVjH7E+s5Re2yg==
   dependencies:
-    nanoid "^3.3.6"
+    nanoid "^3.3.7"
     picocolors "^1.0.0"
     source-map-js "^1.0.2"