Steps to reproduce the issue

Joomla PHP 8.2
Check the Atom Feed
Check the Error Log

Expected result

Actual result

Error Log Entry:
[20-Sep-2023 06:45:49 Europe/Berlin] PHP Deprecated: htmlspecialchars(): Passing null to parameter #1 ($string) of type string is deprecated in /home/www/libraries/src/Document/Renderer/Feed/AtomRenderer.php on line 89

System information (as much as possible)

J 4.3.4
PHP 8.2.10
10.11.4-MariaDB-1:10.11.4+maria~deb11-log

Additional comments