chore(deps): bump postcss from 8.4.29 to 8.4.30 in /frontend

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.29 to 8.4.30.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.29...8.4.30)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

frontend/package.json

@@ -36,7 +36,7 @@
     "firebase": "^10.4.0",
     "firebase-admin": "^11.10.1",
     "next": "13.4.19",
-    "postcss": "8.4.29",
+    "postcss": "8.4.30",
     "prettier-plugin-tailwindcss": "^0.5.4",
     "react": "18.2.0",
     "react-codemirror2": "7.2.1",

frontend/yarn.lock

@@ -4539,10 +4539,10 @@ [email protected]:
     picocolors "^1.0.0"
     source-map-js "^1.0.2"
 
-[email protected].29, postcss@^8, postcss@^8.4.23:
-  version "8.4.29"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.29.tgz#33bc121cf3b3688d4ddef50be869b2a54185a1dd"
-  integrity sha512-cbI+jaqIeu/VGqXEarWkRCCffhjgXc0qjBtXpqJhTBohMUjUQnbBr0xqX3vEKudc4iviTewcJo5ajcec5+wdJw==
+[email protected].30, postcss@^8, postcss@^8.4.23:
+  version "8.4.30"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.30.tgz#0e0648d551a606ef2192a26da4cabafcc09c1aa7"
+  integrity sha512-7ZEao1g4kd68l97aWG/etQKPKq07us0ieSZ2TnFDk11i0ZfDW2AwKHYU8qv4MZKqN2fdBfg+7q0ES06UA73C1g==
   dependencies:
     nanoid "^3.3.6"
     picocolors "^1.0.0"