add callback function support for generator scheduling

depends on  yeoman/yeoman-api#6
required by  jhipster/generator-jhipster#25445
fixes jhipster/generator-jhipster#25444

src/environment-base.ts

@@ -425,7 +425,7 @@ export default class EnvironmentBase extends EventEmitter implements BaseEnviron
     const { schedule = true, ...instantiateOptions } = options;
 
     const generatorInstance = await this.create(generator, instantiateOptions);
-    return this.queueGenerator(generatorInstance, { schedule });
+    return this.queueGenerator(generatorInstance, { schedule: typeof schedule === 'function' ? schedule(generatorInstance) : schedule });
   }
 
   /**