Improve perf ValidationExceptionListener

Author: Danny van Wijk

src/Bundle/Resources/config/services/listener.xml

@@ -21,7 +21,7 @@
             <tag name="kernel.event_listener" event="kernel.request" priority="28" />
         </service>
 
-        <service id="sylius.listener.exception.validation" class="Sylius\Resource\Symfony\Validator\EventListener\ValidationExceptionListener">
+        <service id="sylius.listener.exception.validation" class="Sylius\Resource\Symfony\Validator\EventListener\ValidationExceptionListener" lazy="true">
             <argument type="service" id="serializer" on-invalid="null" />
             <tag name="kernel.event_listener" event="kernel.exception" method="onKernelException" />
         </service>