minor #32770 [SecurityBundle] remove the deprecated "switch_user.stateless" option (xabbuh)

This PR was merged into the 5.0-dev branch.

Discussion
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[SecurityBundle] remove the deprecated "switch_user.stateless" option

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | yes
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

Commits
-------

55d9c516ba remove the deprecated "switch_user.stateless" option

src/Symfony/Bundle/SecurityBundle/CHANGELOG.md

@@ -4,6 +4,7 @@ CHANGELOG
 5.0.0
 -----
 
+ * The `switch_user.stateless` firewall option has been removed.
  * Removed the ability to configure encoders using `argon2i` or `bcrypt` as algorithm, use `auto` instead
  * The `simple_form` and `simple_preauth` authentication listeners have been removed,
    use Guard instead.

src/Symfony/Bundle/SecurityBundle/DependencyInjection/MainConfiguration.php

@@ -244,10 +244,6 @@ class MainConfiguration implements ConfigurationInterface
                     ->scalarNode('provider')->end()
                     ->scalarNode('parameter')->defaultValue('_switch_user')->end()
                     ->scalarNode('role')->defaultValue('ROLE_ALLOWED_TO_SWITCH')->end()
-                    ->booleanNode('stateless')
-                        ->setDeprecated('The "%path%.%node%" configuration key has been deprecated in Symfony 4.1.')
-                        ->defaultValue(false)
-                    ->end()
                 ->end()
             ->end()
         ;

src/Symfony/Bundle/SecurityBundle/DependencyInjection/SecurityExtension.php

@@ -675,7 +675,7 @@ class SecurityExtension extends Extension implements PrependExtensionInterface
         $listener->replaceArgument(3, $id);
         $listener->replaceArgument(6, $config['parameter']);
         $listener->replaceArgument(7, $config['role']);
-        $listener->replaceArgument(9, $stateless ?: $config['stateless']);
+        $listener->replaceArgument(9, $stateless);
 
         return $switchUserListenerId;
     }