downgrade typescript to ^5.9.3 to fix @astrojs/check peer dependency conflict

Agent-Logs-Url: https://github.com/mahata/mahata.github.io/sessions/e2bb9599-2ca3-4e79-bde8-c818392c8c00

Co-authored-by: mahata <23497+mahata@users.noreply.github.com>

Author: Copilot

package-lock.json

@@ -16,7 +16,7 @@
   },
   "devDependencies": {
     "@astrojs/check": "^0.9.8",
-    "typescript": "^6.0.2",
+    "typescript": "^5.9.3",
     "vitest": "^4.1.2"
   }
 }