build(deps): bump postcss from 8.5.3 to 8.5.4

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.3 to 8.5.4.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.5.3...8.5.4)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

package.json

@@ -31,7 +31,7 @@
     "next-auth": "^4.24.11",
     "next-connect": "^1.0.0",
     "next-secure-headers": "^2.2.0",
-    "postcss": "8.5.3",
+    "postcss": "8.5.4",
     "prettier": "^3.5.3",
     "prettier-plugin-tailwindcss": "^0.6.11",
     "react": "18.3.1",