minor #35186 [FrameworkBundle] Fix getUser() phpdoc in AbstractController (natewiebe13)

This PR was merged into the 5.0 branch.

Discussion
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[FrameworkBundle] Fix getUser() phpdoc in AbstractController

| Q             | A
| ------------- | ---
| Branch?       | 5.0
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | Fix #35185
| License       | MIT
| Doc PR        | N/A

This imports the `Symfony\Component\Security\Core\User\UserInterface` as the docs state that it returns `UserInterface` but doesn't use a FQN or import the class. This makes `getUser()` appear to return `Symfony\Bundle\FrameworkBundle\Controller\UserInterface`

Commits
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bba9fd6ccf [FrameworkBundle] Fix getUser() phpdoc in AbstractController

src/Symfony/Bundle/FrameworkBundle/Controller/AbstractController.php

@@ -38,6 +38,7 @@ use Symfony\Component\Routing\RouterInterface;
 use Symfony\Component\Security\Core\Authentication\Token\Storage\TokenStorageInterface;
 use Symfony\Component\Security\Core\Authorization\AuthorizationCheckerInterface;
 use Symfony\Component\Security\Core\Exception\AccessDeniedException;
+use Symfony\Component\Security\Core\User\UserInterface;
 use Symfony\Component\Security\Csrf\CsrfToken;
 use Symfony\Component\Security\Csrf\CsrfTokenManagerInterface;
 use Symfony\Component\Serializer\SerializerInterface;