fix: 'retry-after' headers not being read properly

src/libs/anilist/anilist-do.ts

@@ -359,7 +359,7 @@ export class AnilistDurableObject extends DurableObject {
     if (response.status === 429) {
       const retryAfter = await response
         .json()
-        .then(({ headers }) => headers["Retry-After"]);
+        .then(({ headers }) => new Headers(headers).get("Retry-After"));
       console.log("429, retrying in", retryAfter);
 
       await sleep(Number(retryAfter || 1) * 1000); // specific fallback or ensure logic