PHP deprecation error when deleting a language

Problem/Motivation

When deleting a language, the following message appears (if error reporting is enabled):

Deprecated function: Automatic conversion of false to array is deprecated in Drupal\locale\LocaleDefaultConfigStorage->read() (line 93 of core/modules/locale/src/LocaleDefaultConfigStorage.php).

Drupal\locale\LocaleDefaultConfigStorage->read('language.entity.es') (Line: 494)
Drupal\locale\LocaleConfigManager->getDefaultConfigLangcode('language.entity.es') (Line: 531)
Drupal\locale\LocaleConfigManager->isSupported('language.entity.es') (Line: 127)
Drupal\locale\LocaleConfigSubscriber->updateLocaleStorage(Object, 'es', Array) (Line: 109)
Drupal\locale\LocaleConfigSubscriber->onOverrideChange(Object, 'language.delete_override', Object)
call_user_func(Array, Object, 'language.delete_override', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'language.delete_override') (Line: 78)
Drupal\language\Config\LanguageConfigOverride->delete() (Line: 213)
Drupal\language\Config\LanguageConfigFactoryOverride->onConfigDelete(Object, 'config.delete', Object)
call_user_func(Array, Object, 'config.delete', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'config.delete') (Line: 246)
Drupal\Core\Config\Config->delete() (Line: 232)
Drupal\Core\Config\Entity\ConfigEntityStorage->doDelete(Array) (Line: 456)
Drupal\Core\Entity\EntityStorageBase->delete(Array) (Line: 347)
Drupal\Core\Entity\EntityBase->delete() (Line: 122)
Drupal\Core\Entity\EntityDeleteForm->submitForm(Array, Object)
call_user_func_array(Array, Array) (Line: 114)
Drupal\Core\Form\FormSubmitter->executeSubmitHandlers(Array, Object) (Line: 52)
Drupal\Core\Form\FormSubmitter->doSubmitForm(Array, Object) (Line: 597)
Drupal\Core\Form\FormBuilder->processForm('language_delete_form', Array, Object) (Line: 325)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 73)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 592)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 181)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object, 1, 1) (Line: 704)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

Steps to reproduce

On an English site:

1. Enable error reporting
2. Add Spanish
3. Delete Spanish