/usr/share/gosa/plugins/ is in gosa-plugin-kolab 2.7.4+reloaded3-3.
This file is owned by root:root, with mode 0o755.
..
/usr/share/gosa/plugins/admin/
/usr/share/gosa/plugins/admin/systems/
/usr/share/gosa/plugins/admin/systems/services/
/usr/share/gosa/plugins/admin/systems/services/kolab/
/usr/share/gosa/plugins/admin/systems/services/kolab/class_servKolab.inc
/usr/share/gosa/plugins/admin/systems/services/kolab/servkolab.tpl
/usr/share/gosa/plugins/personal/
/usr/share/gosa/plugins/personal/connectivity/
/usr/share/gosa/plugins/personal/connectivity/kolab/
/usr/share/gosa/plugins/personal/connectivity/kolab/class_kolabAccount.inc
/usr/share/gosa/plugins/personal/connectivity/kolab/kolab.tpl
/usr/share/gosa/plugins/personal/mail/
/usr/share/gosa/plugins/personal/mail/kolab/
/usr/share/gosa/plugins/personal/mail/kolab/class_mail-methods-kolab.inc
/usr/share/gosa/plugins/personal/mail/kolab/class_mail-methods-kolab22.inc
/usr/share/gosa/plugins/personal/mail/kolab/class_mail-methods-kolabNoImap.inc