feat(Rest): switch queue to AsyncQueue (#4835)

Co-authored-by: Sugden <28943913+NotSugden@users.noreply.github.com>

src/rest/RESTManager.js

@@ -35,19 +35,6 @@ class RESTManager {
     return Endpoints.CDN(this.client.options.http.cdn);
   }
 
-  push(handler, apiRequest) {
-    return new Promise((resolve, reject) => {
-      handler
-        .push({
-          request: apiRequest,
-          resolve,
-          reject,
-          retries: 0,
-        })
-        .catch(reject);
-    });
-  }
-
   request(method, url, options = {}) {
     const apiRequest = new APIRequest(this, method, url, options);
     let handler = this.handlers.get(apiRequest.route);
@@ -57,7 +44,7 @@ class RESTManager {
       this.handlers.set(apiRequest.route, handler);
     }
 
-    return this.push(handler, apiRequest);
+    return handler.push(apiRequest);
   }
 
   get endpoint() {