fix: ページカウントのズレを修正

src/routes/(DefaultStyle)/[slug]/+page.server.js

@@ -5,7 +5,7 @@ export async function load({params}){
     const postList = await Metas()
 
     const posts = postList.slice(pageNo*12, (pageNo+1)*12);
-    const lastPage = Math.trunc(postList.length/12);
-
+    const lastPage = Math.ceil(postList.length/12)-1;
+    
     return {posts, pageNo, lastPage}
 }