[Form] Mention that choice labels support TranslatableInterface objects

Author: javiereguiluz

reference/forms/types/options/choice_label.rst.inc

@@ -29,6 +29,12 @@ more control::
         },
     ]);
 
+.. versionadded:: 6.2
+
+    Starting from Symfony 6.2, you can use any object that implements
+    :class:`Symfony\\Contracts\\Translation\\TranslatableInterface` as the value
+    of the choice label.
+
 This method is called for *each* choice, passing you the ``$choice`` and
 ``$key`` from the choices array (additional ``$value`` is related to `choice_value`_).
 This will give you: