fe_users: usergroup not recognized as comma separated values anymore

[klodeckl]

vidi checks if a field is a comma separated value: maxitems should be > 1 (public function hasRelationWithCommaSeparatedValues in Classes/Tca/FieldService.php)

But in current TYPO3 11.5.34 maxitems is not defined for the field usergroup. That leads to wrong results.

Adding
$GLOBALS['TCA']['fe_users']['columns']['usergroup']['config']['maxitems'] = 100;
in TCA/Overrides/fe_users.php solves it.

Tested with vidi dev-main, 6.0 an 5.3, composer mode.