refactor: remove timer utilities from Client (#6113)

src/rest/APIRequest.js

@@ -59,14 +59,14 @@ class APIRequest {
     }
 
     const controller = new AbortController();
-    const timeout = this.client.setTimeout(() => controller.abort(), this.client.options.restRequestTimeout);
+    const timeout = setTimeout(() => controller.abort(), this.client.options.restRequestTimeout).unref();
     return fetch(url, {
       method: this.method,
       headers,
       agent,
       body,
       signal: controller.signal,
-    }).finally(() => this.client.clearTimeout(timeout));
+    }).finally(() => clearTimeout(timeout));
   }
 }
 

src/rest/RESTManager.js

@@ -18,10 +18,9 @@ class RESTManager {
     this.globalReset = null;
     this.globalDelay = null;
     if (client.options.restSweepInterval > 0) {
-      const interval = client.setInterval(() => {
+      this.sweepInterval = setInterval(() => {
         this.handlers.sweep(handler => handler._inactive);
-      }, client.options.restSweepInterval * 1000);
-      interval.unref();
+      }, client.options.restSweepInterval * 1000).unref();
     }
   }
 

src/rest/RequestHandler.js

@@ -71,10 +71,10 @@ class RequestHandler {
 
   globalDelayFor(ms) {
     return new Promise(resolve => {
-      this.manager.client.setTimeout(() => {
+      setTimeout(() => {
         this.manager.globalDelay = null;
         resolve();
-      }, ms);
+      }, ms).unref();
     });
   }