refactor: builders can return non-observable output

Author: hansl

packages/angular_devkit/architect/builders/false.ts

@@ -5,10 +5,9 @@
  * Use of this source code is governed by an MIT-style license that can be
  * found in the LICENSE file at https://angular.io/license
  */
-import { of } from 'rxjs';
 import { createBuilder } from '../src/index2';
 
-export default createBuilder(() => of({
+export default createBuilder(() => ({
   success: false,
   error: 'False builder always errors.',
 }));

packages/angular_devkit/architect/builders/true.ts

@@ -5,7 +5,6 @@
  * Use of this source code is governed by an MIT-style license that can be
  * found in the LICENSE file at https://angular.io/license
  */
-import { of } from 'rxjs';
 import { createBuilder } from '../src/index2';
 
-export default createBuilder(() => of({ success: true }));
+export default createBuilder(() => ({ success: true }));