Changed the way to set the response body

Refer to the following:

  https://github.com/datocms/astro-website/blob/ff4165c327308ad13d3eebd3bfd3ea6a4c82bc70/src/pages/og-card/index.png.ts#L195-L198

Author: koron

2025/src/pages/og.png.ts

@@ -1,7 +1,8 @@
 import { ogImage } from "@/components/OgImage";
 
 export async function GET() {
-  const body = await ogImage();
+  const img = await ogImage();
+  const body = await img.toBuffer();
 
   return new Response(body, {
     headers: {