Bump postcss from 8.4.21 to 8.4.31 in /frontend

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: direct:development
...

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

frontend/package.json

@@ -37,7 +37,7 @@
   "devDependencies": {
     "@types/lodash": "^4.14.191",
     "autoprefixer": "^10.4.14",
-    "postcss": "^8.4.21",
+    "postcss": "^8.4.31",
     "tailwindcss": "^3.2.7"
   }
 }

frontend/yarn.lock

@@ -2280,10 +2280,10 @@ nano-css@^5.3.1:
     stacktrace-js "^2.0.2"
     stylis "^4.0.6"
 
-nanoid@^3.3.4:
-  version "3.3.4"
-  resolved "https://registry.npmjs.org/nanoid/-/nanoid-3.3.4.tgz"
-  integrity sha512-MqBkQh/OHTS2egovRtLk45wEyNXwF+cokD+1YPf9u5VfJiRdAiRwB2froX5Co9Rh20xs4siNPm8naNotSD6RBw==
+nanoid@^3.3.4, 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==
 
 natural-compare@^1.4.0:
   version "1.4.0"
@@ -2571,12 +2571,12 @@ [email protected]:
     picocolors "^1.0.0"
     source-map-js "^1.0.2"
 
-postcss@^8.0.9, postcss@^8.4.21:
-  version "8.4.21"
-  resolved "https://registry.npmjs.org/postcss/-/postcss-8.4.21.tgz"
-  integrity sha512-tP7u/Sn/dVxK2NnruI4H9BG+x+Wxz6oeZ1cJ8P6G/PZY0IKk4k/63TDsQf2kQq3+qoJeLm2kIBUNlZe3zgb4Zg==
+postcss@^8.0.9, postcss@^8.4.31:
+  version "8.4.31"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.31.tgz#92b451050a9f914da6755af352bdc0192508656d"
+  integrity sha512-PS08Iboia9mts/2ygV3eLpY5ghnUcfLV/EXTOW1E2qYxJKGGBUtNjN76FYHnMs36RmARn41bC0AZmn+rR0OVpQ==
   dependencies:
-    nanoid "^3.3.4"
+    nanoid "^3.3.6"
     picocolors "^1.0.0"
     source-map-js "^1.0.2"