Refactor id computation in [id].vue

Author: Enokisan

content/ja/02.concepts/03.routing/.template/solutions/pages/posts/[id].vue

@@ -1,6 +1,6 @@
 <script setup lang="ts">
 const route = useRoute()
-const id = computed(() => route.params.id)
+const id = route.params.id
 </script>
 
 <template>