Address GH feedback

Author: mpdude

UPGRADE.md

@@ -5,6 +5,12 @@
 Use of the PARTIAL keyword is not deprecated anymore in DQL when used with a hydrator
 that is not creating entities, such as the ArrayHydrator.
 
+## Deprecate `\Doctrine\ORM\Query\Parser::setCustomOutputTreeWalker()`
+
+Use the `\Doctrine\ORM\Query::HINT_CUSTOM_OUTPUT_WALKER` query hint to set the output walker
+class instead of setting it through the `\Doctrine\ORM\Query\Parser::setCustomOutputTreeWalker()` method
+on the parser instance.
+
 # Upgrade to 2.19
 
 ## Deprecate calling `ClassMetadata::getAssociationMappedByTargetField()` with the owning side of an association

src/Query/Parser.php

@@ -203,7 +203,7 @@ public function setCustomOutputTreeWalker($className)
         Deprecation::trigger(
             'doctrine/orm',
             'https://github.com/doctrine/orm/pull/11641',
-            '%s is deprecated, set the output walker class in a query hint instead',
+            '%s is deprecated, set the output walker class with the \Doctrine\ORM\Query::HINT_CUSTOM_OUTPUT_WALKER query hint instead',
             __METHOD__
         );