chore(deps): update dependency postcss to v8.5.6

Author: renovate[bot]

package.json

@@ -101,7 +101,7 @@
     "jest-environment-jsdom": "29.7.0",
     "lint-staged": "15.4.3",
     "npm-run-all2": "7.0.2",
-    "postcss": "8.5.4",
+    "postcss": "8.5.6",
     "postcss-preset-env": "10.1.5",
     "prettier": "3.5.3",
     "react": "18.3.1",