Minor: Fix return types - refs BT#21561

public/main/gradebook/lib/be/abstractlink.class.php

@@ -754,12 +754,7 @@ abstract class AbstractLink implements GradebookItem
         return [];
     }
 
-    /**
-     * @param Doctrine\DBAL\Driver\Statement|null $result
-     *
-     * @return array
-     */
-    private static function create_objects_from_sql_result($result)
+    private static function create_objects_from_sql_result(\Doctrine\DBAL\Result $result): array
     {
         $links = [];
         $allow = ('true' === api_get_setting('gradebook.allow_gradebook_stats'));

public/main/gradebook/lib/be/category.class.php

@@ -420,7 +420,7 @@ class Category implements GradebookItem
      * @param ?bool $order_by Whether to show all "session"
      *                            categories (true) or hide them (false) in case there is no session id
      *
-     * @return array
+     * @return array<static>
      * @throws \Doctrine\DBAL\Exception
      * @throws Exception
      */