Passing Url object to RedirectResponse instead of string on dompdf error

Problem/Motivation

When a views PDF can't be generated due to an error, the error handlers attempt to send a RedirectResponse to "", but passing a Url object to the symfony RedirectResponse constructor instead of a string.

$url = $executable->hasUrl() ? $executable->getUrl()->toString() : Url::fromRoute('<front>');
$event->setResponse(new RedirectResponse($url));

Steps to reproduce

Trigger an error when generating a views PDF, instead of being redirected to the homepage and see the debug output and actual errors, you will see an error along the lines of:

Recoverable fatal error: Object of class Drupal\Core\Url could not be converted to string in Drupal\Component\Utility\UrlHelper::isExternal()