fix(modal): fix demo which lost jsx (#2314)

Author: shenjunjian

examples/sites/demos/pc/app/modal/modal-fn-slots-composition-api.vue

@@ -19,7 +19,7 @@
   </div>
 </template>
 
-<script setup>
+<script setup lang="jsx">
 import { Button as TinyButton, Modal, Link } from '@opentiny/vue'
 import { ref } from 'vue'