build(deps): bump postcss from 8.4.16 to 8.4.31 in /next

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.16 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@8.4.16...8.4.31)

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

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

next/yarn.lock

@@ -8904,15 +8904,6 @@ __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"
@@ -9475,7 +9466,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"postcss@npm:8.4.31":
+"postcss@npm:8.4.31, postcss@npm:^8.3.11":
   version: 8.4.31
   resolution: "postcss@npm:8.4.31"
   dependencies:
@@ -9486,17 +9477,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"postcss@npm:^8.3.11":
-  version: 8.4.16
-  resolution: "postcss@npm:8.4.16"
-  dependencies:
-    nanoid: ^3.3.4
-    picocolors: ^1.0.0
-    source-map-js: ^1.0.2
-  checksum: 10eee25efd77868036403858577da0cefaf2e0905feeaba5770d5438ccdddba3d01cba8063e96b8aac4c6daa0ed413dd5ae0554a433a3c4db38df1d134cffc1f
-  languageName: node
-  linkType: hard
-
 "postinstall-postinstall@npm:^2.1.0":
   version: 2.1.0
   resolution: "postinstall-postinstall@npm:2.1.0"