Update passwords.rst

Add use for clarity

Author: Synxgz

security/passwords.rst

@@ -500,6 +500,7 @@ the user provider::
     namespace App\Security;
 
     // ...
+    use Symfony\Component\Security\Core\User\PasswordAuthenticatedUserInterface;
     use Symfony\Component\Security\Core\User\PasswordUpgraderInterface;
 
     class UserProvider implements UserProviderInterface, PasswordUpgraderInterface