aiContent->listExternalPages() fails when externalId is null.

[jdsdev]

aiContent->listExternalPages() exits with the following error if any external pages have a null value for externalId:

Exception 'TypeError' with message 'Cannot assign null to property Intercom\AiContent\Types\ExternalPage::$externalId of type string'

in /var/www/html/cms/vendor/intercom/intercom-php/src/AiContent/Types/ExternalPage.php:128

External pages created through the Intercom UI do not appear to have an externalId.

PHP: 8.4.18
intercom/intercom-php: 5.0.2