fix lastmod date in sitemap

Author: davemooreuws

src/app/(sitemaps)/sitemap-0.xml/route.ts

@@ -9,12 +9,11 @@ interface SitemapItem {
   priority: number
 }
 
-const lastmod = new Date().toISOString()
 // Function to construct the XML structure of the sitemap index.
 export async function GET() {
   const pages: SitemapItem[] = allDocs.map((page) => ({
     loc: page.slug === '' ? URL : `${URL}/${page.slug}`,
-    lastmod,
+    lastmod: new Date(page.lastModified).toISOString(),
     changefreq: 'daily',
     priority: 0.7,
   }))