remove getContainer overwrites in tests

Since 5.0 the parent implementation throws an exception anyway making the overwrites obsolete, see symfony/symfony#31202

Tests/Functional/app/AppKernel.php

@@ -12,7 +12,6 @@
 namespace Symfony\Bundle\SecurityBundle\Tests\Functional\app;
 
 use Symfony\Component\Config\Loader\LoaderInterface;
-use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\Filesystem\Filesystem;
 use Symfony\Component\HttpKernel\Kernel;
 
@@ -99,13 +98,4 @@ protected function getKernelParameters(): array
 
         return $parameters;
     }
-
-    public function getContainer(): ContainerInterface
-    {
-        if (!$this->container) {
-            throw new \LogicException('Cannot access the container on a non-booted kernel. Did you forget to boot it?');
-        }
-
-        return parent::getContainer();
-    }
 }