/var/lib/lemonldap-ng/manager/skins/default is in liblemonldap-ng-manager-perl 1.2.5-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/lemonldap-ng/manager-skins/default
/usr/share/lemonldap-ng/manager-skins/default