chore(deps-dev): Bump postcss from 8.5.15 to 8.5.16 in /web

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.15 to 8.5.16.
- [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/8.5.15...8.5.16)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.16
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

web/package.json

@@ -19,7 +19,7 @@
     "@types/react-dom": "^18.3.5",
     "@vitejs/plugin-react": "^4.3.4",
     "autoprefixer": "^10.4.20",
-    "postcss": "^8.4.49",
+    "postcss": "^8.5.16",
     "tailwindcss": "^3.4.17",
     "typescript": "^5.7.3",
     "vite": "^6.0.7"