Bump postcss from 8.4.1 to 8.4.4 in /frontend

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.1 to 8.4.4.
- [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/8.4.1...8.4.4)

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

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

frontend/package.json

@@ -15,7 +15,7 @@
         "laravel-mix": "^6",
         "lodash": "^4.17.21",
         "lodash.clonedeep": "^4.5.0",
-        "postcss": "^8.3.11",
+        "postcss": "^8.4.4",
         "resolve-url-loader": "^4.0.0",
         "sass": "^1.43.3",
         "sass-loader": "^12.2.0",

frontend/yarn.lock

@@ -5320,10 +5320,10 @@ postcss@^7.0.35, postcss@^7.0.36:
     picocolors "^0.2.1"
     source-map "^0.6.1"
 
-postcss@^8.2.15, postcss@^8.3.11:
-  version "8.4.1"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.1.tgz#73051f825509ad1a716ef500108001bf3d1fa8f7"
-  integrity sha512-WqLs/TTzXdG+/A4ZOOK9WDZiikrRaiA+eoEb/jz2DT9KUhMNHgP7yKPO8vwi62ZCsb703Gwb7BMZwDzI54Y2Ag==
+postcss@^8.2.15, postcss@^8.4.4:
+  version "8.4.4"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.4.tgz#d53d4ec6a75fd62557a66bb41978bf47ff0c2869"
+  integrity sha512-joU6fBsN6EIer28Lj6GDFoC/5yOZzLCfn0zHAn/MYXI7aPt4m4hK5KC5ovEZXy+lnCjmYIbQWngvju2ddyEr8Q==
   dependencies:
     nanoid "^3.1.30"
     picocolors "^1.0.0"