refactor(@angular-devkit/architect): remove usage of isPromise

The isPromise utility was only used in one place in create-job-handler.ts. It has been replaced with an inline check for thenables. The utility is now marked as deprecated in @angular-devkit/core.

Author: clydin

packages/angular_devkit/architect/src/jobs/create-job-handler.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import { BaseException, JsonValue, isPromise, logging } from '@angular-devkit/core';
+import { BaseException, JsonValue, logging } from '@angular-devkit/core';
 import {
   Observable,
   Observer,
@@ -161,7 +161,7 @@ export function createJobHandler<A extends JsonValue, I extends JsonValue, O ext
       subject.next({ kind: JobOutboundMessageKind.Start, description });
       let result = fn(argument, newContext);
       // If the result is a promise, simply wait for it to complete before reporting the result.
-      if (isPromise(result)) {
+      if (typeof (result as PromiseLike<O>)?.then === 'function') {
         result = from(result);
       } else if (!isObservable(result)) {
         result = of(result);

packages/angular_devkit/core/src/utils/lang.ts

@@ -10,6 +10,8 @@
 
 /**
  * Determine if the argument is shaped like a Promise
+ *
+ * @deprecated Use `typeof obj?.then === 'function'` instead.
  */
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 export function isPromise(obj: any): obj is Promise<any> {