Pin postcss to 8.5.23 via npm override

Co-authored-by: abdulahmad307 <204748719+abdulahmad307@users.noreply.github.com>

Author: Copilot

package-lock.json

@@ -25,5 +25,8 @@
     },
     "devDependencies": {
         "vitest": "^4.1.10"
+    },
+    "overrides": {
+        "postcss": "8.5.23"
     }
 }