fix(regression): newCollection accepts collections

Signed-off-by: Sami Mazouz <sychocouldy@gmail.com>

extensions/mentions/src/Api/LoadMentionedByRelationship.php

@@ -47,7 +47,6 @@ class LoadMentionedByRelationship
         $loadable = null;
 
         if ($data instanceof Discussion) {
-            // @phpstan-ignore-next-line
             $loadable = $data->newCollection($data->posts)->filter(function ($post) {
                 return $post instanceof Post;
             });