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

Author: renovate[bot]

package-lock.json

@@ -77,7 +77,7 @@
     "jest": "29.7.0",
     "jest-environment-jsdom": "29.7.0",
     "lint-staged": "15.4.3",
-    "postcss": "8.5.3",
+    "postcss": "8.5.6",
     "prettier": "3.5.3",
     "react": "18.3.1",
     "react-dom": "18.3.1",