Revert "bug symfony#12600 [Doctrine] Don't mention invokable listeners in 4.3 (javiereguiluz)"

This reverts commit 9949cfd, reversing
changes made to c2f93ef.

Author: wouterj

doctrine/events.rst

@@ -272,7 +272,8 @@ with the ``doctrine.orm.entity_listener`` tag:
                         entity_manager: 'custom'
 
                         # by default, Symfony looks for a method called after the event (e.g. postUpdate())
-                        # but you can configure a custom method name with the 'method' option
+                        # if it doesn't exist, it tries to execute the '__invoke()' method, but you can
+                        # configure a custom method name with the 'method' option
                         method: 'checkUserChanges'
 
     .. code-block:: xml
@@ -291,7 +292,8 @@ with the ``doctrine.orm.entity_listener`` tag:
                         * 'entity_manager': define it if the listener is not associated to the
                         *                   default entity manager
                         * 'method': by default, Symfony looks for a method called after the event (e.g. postUpdate())
-                        *           but you can configure a custom method name with the 'method' option
+                        *           if it doesn't exist, it tries to execute the '__invoke()' method, but
+                        *           you can configure a custom method name with the 'method' option
                     -->
                     <tag name="doctrine.orm.entity_listener"
                         event="postUpdate"
@@ -321,8 +323,9 @@ with the ``doctrine.orm.entity_listener`` tag:
                 // you can also associate an entity listener to a specific entity manager
                 'entity_manager' => 'custom',
 
-                // by default, Symfony looks for a method called after the event (e.g. postUpdate()),
-                // but you can configure a custom method name with the 'method' option
+                // by default, Symfony looks for a method called after the event (e.g. postUpdate())
+                // if it doesn't exist, it tries to execute the '__invoke()' method, but you can
+                // configure a custom method name with the 'method' option
                 'method' => 'checkUserChanges',
             ])
         ;