Using null as an array offset is deprecated error on admin/content and admin/people

Problem/Motivation

On the latest state of the main branch when visiting admin/content I get the following error equal to the number of nodes on the page.

Deprecated function: Using null as an array offset is deprecated, use an empty string instead in Drupal\Core\Entity\ContentEntityBase->hasTranslation() (line 984 of /var/www/html/repos/drupal/core/lib/Drupal/Core/Entity/ContentEntityBase.php).
Drupal\Core\Entity\ContentEntityBase->hasTranslation() (Line: 1911)
Twig\Extension\CoreExtension::getAttribute() (Line: 46)
__TwigTemplate_104c123cb839873dcefb442f12b3c12d->doDisplay() (Line: 402)
Twig\Template->yield() (Line: 386)
Twig\Template->render() (Line: 51)
Twig\TemplateWrapper->render() (Line: 35)
Drupal\Core\Template\TwigThemeEngine->renderTemplate() (Line: 388)
Drupal\Core\Theme\ThemeManager->render() (Line: 485)
Drupal\Core\Render\Renderer->doRender() (Line: 211)
Drupal\Core\Render\Renderer->render() (Line: 1809)
Drupal\views\Plugin\views\field\FieldPluginBase->theme() (Line: 767)
Drupal\views\Plugin\views\style\StylePluginBase->elementPreRenderRow()
call_user_func_array() (Line: 107)
Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 895)
Drupal\Core\Render\Renderer->doCallback() (Line: 428)
Drupal\Core\Render\Renderer->doRender() (Line: 211)
Drupal\Core\Render\Renderer->render() (Line: 704)
Drupal\views\Plugin\views\style\StylePluginBase->renderFields() (Line: 579)
Drupal\views\Plugin\views\style\StylePluginBase->renderGrouping() (Line: 467)
Drupal\views\Plugin\views\style\StylePluginBase->render() (Line: 2207)
Drupal\views\Plugin\views\display\DisplayPluginBase->render() (Line: 1586)
Drupal\views\ViewExecutable->render() (Line: 201)
Drupal\views\Plugin\views\display\Page->execute() (Line: 1681)
Drupal\views\ViewExecutable->executeDisplay() (Line: 80)
Drupal\views\Element\View::preRenderViewElement()
call_user_func_array() (Line: 107)
Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 895)
Drupal\Core\Render\Renderer->doCallback() (Line: 428)
Drupal\Core\Render\Renderer->doRender() (Line: 211)
Drupal\Core\Render\Renderer->render() (Line: 242)
Drupal\Core\Render\MainContent\HtmlRenderer->{closure:Drupal\Core\Render\MainContent\HtmlRenderer::prepare():235}() (Line: 619)
Drupal\Core\Render\Renderer::{closure:Drupal\Core\Render\Renderer::executeInRenderContext():619}()
Fiber->resume() (Line: 634)
Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 235)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare() (Line: 131)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse() (Line: 69)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray() (Line: 246)
Symfony\Component\EventDispatcher\EventDispatcher::{closure:Symfony\Component\EventDispatcher\EventDispatcher::optimizeListeners():241}() (Line: 206)
Symfony\Component\EventDispatcher\EventDispatcher->callListeners() (Line: 56)
Symfony\Component\EventDispatcher\EventDispatcher->dispatch() (Line: 188)
Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53)
Drupal\Core\StackMiddleware\Session->handle() (Line: 30)
Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 114)
Drupal\page_cache\StackMiddleware\PageCache->pass() (Line: 88)
Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 61)
Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 54)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 753)
Drupal\Core\DrupalKernel->handle() (Line: 19)

same happens visiting admin/people leading also for a deprecation error for each user account created causing the exact same error as the one on admin/content. the errors dont show up with claro set as the admin theme while the errors show with the admin theme.

Steps to reproduce

• set the theme to admin (experimental) on admin/appearance
• go to admin/content
• make sure you have at least one or two nodes already created.
• go to admin/people
• make sure you have at least one or two user accounts created

Proposed resolution

Fix the deprecation on admin/content and admin/people

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet