Release 8.1 breaks with PHP 7.4

Drupal 9 still supports PHP 7.4, but the rabbit_hole module's latest release (1.0.0) introduced a syntax change that isn't compatible with PHP 7.4.

possible solution:

Patch the Module Manually :

edit the module file BehaviorSettingsManager.php and remove the trailing comma. This is a quick fix but not ideal for long-term maintenance.

If possible, consider upgrading your PHP version since PHP 7.4 is end-of-life (EOL) as of November 2022.

Related: https://stackoverflow.com/questions/40271763/correcting-php-version-requ...

Maybe a better solution would be to remove Drupal 9.5 from the supported versions and require PHP 8. Both Drupal 9.5 and PHP 7.4 are unsupported so the maintainers' efforts are better spent elsewhere.