Add the versionadded directive

Author: javiereguiluz

reference/constraints/Time.rst

@@ -115,4 +115,8 @@ Option     Pattern                          Correct value   Incorrect value
 ``false``  ``/^(\d{2}):(\d{2})$/``          ``12:00``       ``12:00:00``
 =========  ===============================  ==============  ================
 
+.. versionadded:: 6.4
+
+    The ``withSeconds`` option was introduced in Symfony 6.4.
+
 .. include:: /reference/constraints/_payload-option.rst.inc