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](https://github.com/postcss/postcss/compare/8.4.21...8.4.31)

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

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

yarn.lock

@@ -6884,15 +6884,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"nanoid@npm:^3.3.4":
-  version: 3.3.4
-  resolution: "nanoid@npm:3.3.4"
-  bin:
-    nanoid: bin/nanoid.cjs
-  checksum: 2fddd6dee994b7676f008d3ffa4ab16035a754f4bb586c61df5a22cf8c8c94017aadd360368f47d653829e0569a92b129979152ff97af23a558331e47e37cd9c
-  languageName: node
-  linkType: hard
-
 "nanoid@npm:^3.3.6":
   version: 3.3.6
   resolution: "nanoid@npm:3.3.6"
@@ -7587,25 +7578,14 @@ __metadata:
   languageName: node
   linkType: hard
 
-"postcss@npm:^8.4.21":
+"postcss@npm:^8.4.21, postcss@npm:^8.4.23":
-  version: 8.4.21
+  version: 8.4.31
-  resolution: "postcss@npm:8.4.21"
+  resolution: "postcss@npm:8.4.31"
-  dependencies:
-    nanoid: ^3.3.4
-    picocolors: ^1.0.0
-    source-map-js: ^1.0.2
-  checksum: e39ac60ccd1542d4f9d93d894048aac0d686b3bb38e927d8386005718e6793dbbb46930f0a523fe382f1bbd843c6d980aaea791252bf5e176180e5a4336d9679
-  languageName: node
-  linkType: hard
-
-"postcss@npm:^8.4.23":
-  version: 8.4.24
-  resolution: "postcss@npm:8.4.24"
   dependencies:
     nanoid: ^3.3.6
     picocolors: ^1.0.0
     source-map-js: ^1.0.2
-  checksum: 814e2126dacfea313588eda09cc99a9b4c26ec55c059188aa7a916d20d26d483483106dc5ff9e560731b59f45c5bb91b945dfadc670aed875cc90ddbbf4e787d
+  checksum: 1d8611341b073143ad90486fcdfeab49edd243377b1f51834dc4f6d028e82ce5190e4f11bb2633276864503654fb7cab28e67abdc0fbf9d1f88cad4a0ff0beea
   languageName: node
   linkType: hard