Error when webform is uninstalled

Problem/Motivation

When Webform and Require Login modules are both installed, and then webform is uninstalled, the site produces a white-screen error.

Steps to reproduce

1. Install Webform and Require Login.
2. Visit the Require Login configuration page and confirm Webforms and Webform are listed options.
3. Save the configuration, no actual changes needed.
4. Uninstall all Webform-related modules.
5. Visit the homepage while not logged in to get an error.

Drupal\Component\Plugin\Exception\PluginNotFoundException: The "webform" plugin does not exist. Valid plugin IDs for Drupal\Core\Condition\ConditionManager are: request_path, response_status, current_theme, user_role, entity_bundle:block_content, entity_bundle:comment, entity_bundle:contact_message, entity_bundle:menu_link_content, entity_bundle:node, entity_bundle:shortcut, entity_bundle:taxonomy_term in Drupal\Core\Plugin\DefaultPluginManager->doGetDefinition() (line 53 of /core/lib/Drupal/Component/Plugin/Discovery/DiscoveryTrait.php).

#0 /core/lib/Drupal/Component/Plugin/Discovery/DiscoveryCachedTrait.php(25): Drupal\Core\Plugin\DefaultPluginManager->doGetDefinition(Array, 'webform', true)
#1 /core/lib/Drupal/Core/Plugin/Factory/ContainerFactory.php(16): Drupal\Core\Plugin\DefaultPluginManager->getDefinition('webform')
#2 /core/lib/Drupal/Core/Condition/ConditionManager.php(67): Drupal\Core\Plugin\Factory\ContainerFactory->createInstance('webform', Array)
#3 /core/lib/Drupal/Core/Plugin/DefaultLazyPluginCollection.php(81): Drupal\Core\Condition\ConditionManager->createInstance('webform', Array)
#4 /core/lib/Drupal/Component/Plugin/LazyPluginCollection.php(80): Drupal\Core\Plugin\DefaultLazyPluginCollection->initializePlugin('webform')
#5 /core/lib/Drupal/Core/Condition/ConditionPluginCollection.php(26): Drupal\Component\Plugin\LazyPluginCollection->get('webform')
#6 /core/lib/Drupal/Component/Plugin/LazyPluginCollection.php(149): Drupal\Core\Condition\ConditionPluginCollection->get('webform')
#7 /modules/contrib/require_login/src/LoginRequirementsManager.php(169): Drupal\Component\Plugin\LazyPluginCollection->getIterator()
#8 /modules/contrib/require_login/src/EventSubscriber/LoginEventSubscriber.php(70): Drupal\require_login\LoginRequirementsManager->evaluate()
#9 [internal function]: Drupal\require_login\EventSubscriber\LoginEventSubscriber->onRequestRedirect(Object(Symfony\Component\HttpKernel\Event\RequestEvent), 'kernel.request', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#10 /core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php(111): call_user_func(Array, Object(Symfony\Component\HttpKernel\Event\RequestEvent), 'kernel.request', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#11 /var/lib/tugboat/stm/vendor/symfony/http-kernel/HttpKernel.php(157): Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object(Symfony\Component\HttpKernel\Event\RequestEvent), 'kernel.request')
#12 /var/lib/tugboat/stm/vendor/symfony/http-kernel/HttpKernel.php(76): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#13 /core/lib/Drupal/Core/StackMiddleware/Session.php(53): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#14 /core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#15 /core/lib/Drupal/Core/StackMiddleware/ContentLength.php(28): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#16 /core/modules/big_pipe/src/StackMiddleware/ContentLength.php(32): Drupal\Core\StackMiddleware\ContentLength->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#17 /core/modules/page_cache/src/StackMiddleware/PageCache.php(201): Drupal\big_pipe\StackMiddleware\ContentLength->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#18 /core/modules/page_cache/src/StackMiddleware/PageCache.php(138): Drupal\page_cache\StackMiddleware\PageCache->fetch(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#19 /core/modules/page_cache/src/StackMiddleware/PageCache.php(87): Drupal\page_cache\StackMiddleware\PageCache->lookup(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#20 /core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#21 /core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#22 /core/lib/Drupal/Core/StackMiddleware/AjaxPageState.php(36): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#23 /core/lib/Drupal/Core/StackMiddleware/StackedHttpKernel.php(51): Drupal\Core\StackMiddleware\AjaxPageState->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#24 /core/lib/Drupal/Core/DrupalKernel.php(741): Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#25 /index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request))
#26 {main}