Merge branch '6.4' into 7.0

* 6.4:
  -
  Update multiple_kernels.rst
  Add missing use statements

Author: OskarStark

configuration/multiple_kernels.rst

@@ -117,7 +117,8 @@ resources::
     // src/Kernel.php
     namespace Shared;
 
-    // ...
+    use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
+    use Symfony\Component\Routing\Loader\Configurator\RoutingConfigurator;
 
     class Kernel extends BaseKernel
     {
@@ -257,7 +258,8 @@ the application ID to run under CLI context::
 
     // bin/console
     use Shared\Kernel;
-    // ...
+    use Symfony\Component\Console\Input\InputInterface;
+    use Symfony\Component\Console\Input\InputOption;
 
     return function (InputInterface $input, array $context): Application {
         $kernel = new Kernel($context['APP_ENV'], (bool) $context['APP_DEBUG'], $input->getParameterOption(['--id', '-i'], $context['APP_ID']));