refactor: Remove deferred.reject since it's not used

lib/createDeferredTask.js

@@ -1,16 +1,15 @@
 /**
  * Create a deferred task that can be resolved when we call `resolve()`
- * The returned promise will complete only when we call `resolve` or `reject`
+ * The returned promise will complete when we call `resolve`
  * Useful when we want to wait for a tasks that is resolved from an external action
  *
  * @template T
- * @returns {{ resolve: function(*), reject: function(Error), promise: Promise<T|void> }}
+ * @returns {{ resolve: function(*), promise: Promise<T|void> }}
  */
 export default function createDeferredTask() {
     const deferred = {};
-    deferred.promise = new Promise((res, rej) => {
+    deferred.promise = new Promise((res) => {
         deferred.resolve = res;
-        deferred.reject = rej;
     });
 
     return deferred;