refactor: update Ant Design imports to centralized path

- Replaced direct imports from 'antd' with centralized imports from '@/shared/antd-imports' to align with new import rules and improve maintainability.

worklenz-frontend/src/pages/unauthorized/unauthorized.tsx

@@ -1,5 +1,5 @@
 import { useDocumentTitle } from '@/hooks/useDoumentTItle';
-import { Button, Result } from 'antd';
+import { Button, Result } from '@/shared/antd-imports';
 import { useTranslation } from 'react-i18next';
 import { useNavigate } from 'react-router-dom';