docs(searchbar): streamline usage example with script setup syntax (#3406)

Author: treighmawaka

static/usage/v7/searchbar/basic/vue.md

@@ -7,12 +7,7 @@
   <ion-searchbar animated="true" placeholder="Animated"></ion-searchbar>
 </template>
 
-<script lang="ts">
+<script lang="ts" setup>
   import { IonSearchbar } from '@ionic/vue';
-  import { defineComponent } from 'vue';
-
-  export default defineComponent({
-    components: { IonSearchbar },
-  });
 </script>
 ```