Use required classes for Lifecycle Callback examples (#10916)

* Use required classes for Lifecycle Callback examples

* Coding Style fixes

---------

Co-authored-by: Sergii Dolgushev <[email protected]>

Author: SerheyDolgushev

docs/en/cookbook/validation-of-entities.rst

@@ -58,6 +58,10 @@ First Attributes:
 .. code-block:: php
 
     <?php
+    use Doctrine\ORM\Mapping\Entity;
+    use Doctrine\ORM\Mapping\HasLifecycleCallbacks;
+    use Doctrine\ORM\Mapping\PrePersist;
+    use Doctrine\ORM\Mapping\PreUpdate;
 
     #[Entity]
     #[HasLifecycleCallbacks]

docs/en/reference/events.rst

@@ -215,6 +215,10 @@ specific to a particular entity class's lifecycle.
         <?php
         use Doctrine\DBAL\Types\Types;
         use Doctrine\ORM\Event\PrePersistEventArgs;
+        use Doctrine\ORM\Mapping\Entity;
+        use Doctrine\ORM\Mapping\HasLifecycleCallbacks;
+        use Doctrine\ORM\Mapping\PrePersist;
+        use Doctrine\ORM\Mapping\PreUpdate;
 
         #[Entity]
         #[HasLifecycleCallbacks]