npm-dep: bump postcss from 8.4.45 to 8.4.47 in /frontend

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.45 to 8.4.47.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.45...8.4.47)

---
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

@@ -27,7 +27,7 @@
 		"eslint-config-prettier": "^9.1.0",
 		"eslint-plugin-svelte": "^2.44.0",
 		"husky": "^9.1.6",
-		"postcss": "^8.4.45",
+		"postcss": "^8.4.47",
 		"prettier": "^3.3.3",
 		"prettier-plugin-svelte": "^3.2.6",
 		"prettier-plugin-tailwindcss": "^0.6.6",