- Some more fixes for PHP8.5+

src/EntityCollection.php

@@ -322,7 +322,7 @@ class EntityCollection extends \ArrayObject implements \JsonSerializable {
                 case is_string($value):
                     $value = (string) $value;
 
-                    $list[$key] = $item->$value;
+                    $list[(string) $key] = $item->$value;
                     break;
             }
         }