PHP warning `undefined array key 1` from `TCA/Overrides/tt_content.php` line 97

[rintisch]

Hey!

In TYPO3 v13 with PHP 8.3 i get a warning undefined array key 1 in the backend due to

cta/Configuration/TCA/Overrides/tt_content.php

Line 97 in 89cb8a9

--div--;LLL:EXT:core/Resources/Private/Language/Form/locallang_tabs.xlf:language,' . $showItemParts[1]

the full warning is

Core: Error handler (BE): PHP Warning: Undefined array key 1 in /var/www/html/vendor/b13/cta/Configuration/TCA/Overrides/tt_content.php line 97

I guess it's one of these typical PHP8 errors!?