build(deps): bump postcss from 8.4.21 to 8.4.31

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](postcss/postcss@8.4.21...8.4.31)

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

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

Author: dependabot[bot]

yarn.lock

@@ -3514,9 +3514,9 @@ ms@2.1.2, ms@^2.1.1:
   version "2.1.2"
   resolved "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz"
 
-nanoid@^3.3.4:
-  version "3.3.4"
-  resolved "https://registry.npmjs.org/nanoid/-/nanoid-3.3.4.tgz"
+nanoid@^3.3.6:
+  version "3.3.6"
+  resolved "https://registry.yarnpkg.com/nanoid/-/nanoid-3.3.6.tgz#443380c856d6e9f9824267d960b4236ad583ea4c"
 
 natural-compare@^1.4.0:
   version "1.4.0"
@@ -3788,10 +3788,10 @@ postcss-value-parser@^4.1.0, postcss-value-parser@^4.2.0:
   resolved "https://registry.npmjs.org/postcss-value-parser/-/postcss-value-parser-4.2.0.tgz"
 
 postcss@^8.4.19:
-  version "8.4.21"
-  resolved "https://registry.npmjs.org/postcss/-/postcss-8.4.21.tgz"
+  version "8.4.31"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.31.tgz#92b451050a9f914da6755af352bdc0192508656d"
   dependencies:
-    nanoid "^3.3.4"
+    nanoid "^3.3.6"
     picocolors "^1.0.0"
     source-map-js "^1.0.2"