Bump postcss from 8.4.38 to 8.4.39

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.38 to 8.4.39.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.38...8.4.39)

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

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

package.json

@@ -37,7 +37,7 @@
     "eslint-plugin-react": "^7.34.3",
     "eslint-plugin-react-hooks": "^4.6.2",
     "eslint-plugin-react-refresh": "^0.4.7",
-    "postcss": "^8.4.38",
+    "postcss": "^8.4.39",
     "postcss-preset-mantine": "^1.15.0",
     "postcss-simple-vars": "^7.0.1",
     "prettier": "^3.3.2",