Bump postcss from 8.4.38 to 8.4.40 in /frontend

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.38 to 8.4.40.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.38...8.4.40)

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

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

Author: dependabot[bot]

frontend/package.json

@@ -78,7 +78,7 @@
 		"@xstate/inspect": "^0.8.0",
 		"autoprefixer": "^10.4.13",
 		"jest": "^29.7.0",
-		"postcss": "^8.4.35",
+		"postcss": "^8.4.40",
 		"tailwindcss": "^3.3.5",
 		"tailwindcss-blend-mode": "^1.0.0",
 		"ts-jest": "^27.0.4",