[11.9] Allow update_at order by in Projects::pipelines (#710)

Co-authored-by: Graham Campbell <GrahamCampbell@users.noreply.github.com>

Author: jdecool

src/Api/Projects.php

@@ -337,9 +337,9 @@ public function enableRunner(int $project_id, int $runner_id)
      *     @var bool   $yaml_errors returns pipelines with invalid configurations
      *     @var string $name        the name of the user who triggered pipelines
      *     @var string $username    the username of the user who triggered pipelines
-     *     @var string $order_by    order pipelines by id, status, ref, or user_id (default: id)
+     *     @var string $order_by    order pipelines by id, status, ref, updated_at, or user_id (default: id)
      *     @var string $order       sort pipelines in asc or desc order (default: desc)
-     *     @var string $source      The source of the pipeline
+     *     @var string $source      the source of the pipeline
      * }
      *
      * @return mixed
@@ -377,7 +377,7 @@ public function pipelines($project_id, array $parameters = [])
                  ->setNormalizer('updated_before', $datetimeNormalizer)
         ;
         $resolver->setDefined('order_by')
-            ->setAllowedValues('order_by', ['id', 'status', 'ref', 'user_id'])
+            ->setAllowedValues('order_by', ['id', 'status', 'ref', 'updated_at', 'user_id'])
         ;
         $resolver->setDefined('sort')
             ->setAllowedValues('sort', ['asc', 'desc'])