InvalidArgumentException: Class "seven_form_system_theme_settings_alter" does not exist. in Drupal\Core\DependencyInjection\ClassResolver->getInstanceFromDefinition()

Problem/Motivation

After setting seven as the admin theme, opening the theme settings other than seven, crash with the exception.

InvalidArgumentException: Class "seven_form_system_theme_settings_alter" does not exist. in Drupal\Core\DependencyInjection\ClassResolver->getInstanceFromDefinition() (line 32 of core/lib/Drupal/Core/DependencyInjection/ClassResolver.php).
Drupal\Core\Utility\CallableResolver->getCallableFromDefinition() (Line: 592)
Drupal\Core\Theme\ThemeManager->getImplementationsForTheme() (Line: 556)
Drupal\Core\Theme\ThemeManager->alterForTheme() (Line: 620)
Drupal\Core\Theme\ThemeManager->alter() (Line: 893)
Drupal\Core\Form\FormBuilder->prepareForm() (Line: 304)
Drupal\Core\Form\FormBuilder->buildForm() (Line: 73)
Drupal\Core\Controller\FormController->getContentResult()
call_user_func_array() (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 634)
Drupal\Core\Render\Renderer::Drupal\Core\Render\{closure}()
Fiber->start() (Line: 635)
Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 121)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext() (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 183)
Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53)
Drupal\Core\StackMiddleware\Session->handle() (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 118)
Drupal\page_cache\StackMiddleware\PageCache->pass() (Line: 92)
Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 53)
Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 54)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 745)
Drupal\Core\DrupalKernel->handle() (Line: 19)

Is 3531148 relevant?
https://www.drupal.org/project/seven/issues/3531148
I tried renaming theme-settings.php to seven.theme and the error dissapeared.

Steps to reproduce

1. Clean install drupal 11.3.
2. composer require drush/drush
3. composer require 'drupal/seven:^2.0@beta'
4. drush thin seven -y
5. drush config-set system.theme admin seven -y
6. Login as admin and access /admin/appearance/settings/olivero