/usr/include/KF5/calendarsupport/ is in libkf5calendarsupport-dev 4:17.12.3-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/KF5/calendarsupport/archivedialog.h
/usr/include/KF5/calendarsupport/calendarsingleton.h
/usr/include/KF5/calendarsupport/calendarsupport_export.h
/usr/include/KF5/calendarsupport/calprintdefaultplugins.h
/usr/include/KF5/calendarsupport/calprinter.h
/usr/include/KF5/calendarsupport/calprintpluginbase.h
/usr/include/KF5/calendarsupport/categoryconfig.h
/usr/include/KF5/calendarsupport/categoryhierarchyreader.h
/usr/include/KF5/calendarsupport/cellitem.h
/usr/include/KF5/calendarsupport/collectionselection.h
/usr/include/KF5/calendarsupport/eventarchiver.h
/usr/include/KF5/calendarsupport/freebusycalendar.h
/usr/include/KF5/calendarsupport/freebusyitem.h
/usr/include/KF5/calendarsupport/freebusyitemmodel.h
/usr/include/KF5/calendarsupport/freeperiodmodel.h
/usr/include/KF5/calendarsupport/identitymanager.h
/usr/include/KF5/calendarsupport/incidenceviewer.h
/usr/include/KF5/calendarsupport/kcalprefs.h
/usr/include/KF5/calendarsupport/kcalprefs_base.h
/usr/include/KF5/calendarsupport/messagewidget.h
/usr/include/KF5/calendarsupport/plugin.h
/usr/include/KF5/calendarsupport/printplugin.h
/usr/include/KF5/calendarsupport/ui_calprintdayconfig_base.h
/usr/include/KF5/calendarsupport/ui_calprintincidenceconfig_base.h
/usr/include/KF5/calendarsupport/ui_calprintmonthconfig_base.h
/usr/include/KF5/calendarsupport/ui_calprinttodoconfig_base.h
/usr/include/KF5/calendarsupport/ui_calprintweekconfig_base.h
/usr/include/KF5/calendarsupport/utils.h