fixup! Use PHP attributes when creating custom validation constraints

Author: yoannrenard

validation/custom_constraint.rst

@@ -14,6 +14,12 @@ Creating the Constraint Class
 
 First you need to create a Constraint class and extend :class:`Symfony\\Component\\Validator\\Constraint`:
 
+.. versionadded:: 5.2
+
+    The ability to use PHP attributes to configure constraint was introduced in
+    Symfony 5.2. Prior to this, Doctrine Annotations were the only way to
+    annotate constraints.
+
 .. configuration-block::
 
     .. code-block:: php-annotations