/usr/include/KF5/KParts/kparts/ is in libkf5parts-dev 5.18.0-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/KF5/KParts/kparts/browserarguments.h
/usr/include/KF5/KParts/kparts/browserextension.h
/usr/include/KF5/KParts/kparts/browserhostextension.h
/usr/include/KF5/KParts/kparts/browserinterface.h
/usr/include/KF5/KParts/kparts/browseropenorsavequestion.h
/usr/include/KF5/KParts/kparts/browserrun.h
/usr/include/KF5/KParts/kparts/event.h
/usr/include/KF5/KParts/kparts/fileinfoextension.h
/usr/include/KF5/KParts/kparts/guiactivateevent.h
/usr/include/KF5/KParts/kparts/historyprovider.h
/usr/include/KF5/KParts/kparts/htmlextension.h
/usr/include/KF5/KParts/kparts/htmlsettingsinterface.h
/usr/include/KF5/KParts/kparts/kparts_export.h
/usr/include/KF5/KParts/kparts/listingfilterextension.h
/usr/include/KF5/KParts/kparts/listingnotificationextension.h
/usr/include/KF5/KParts/kparts/liveconnectextension.h
/usr/include/KF5/KParts/kparts/mainwindow.h
/usr/include/KF5/KParts/kparts/openurlarguments.h
/usr/include/KF5/KParts/kparts/openurlevent.h
/usr/include/KF5/KParts/kparts/part.h
/usr/include/KF5/KParts/kparts/partactivateevent.h
/usr/include/KF5/KParts/kparts/partbase.h
/usr/include/KF5/KParts/kparts/partmanager.h
/usr/include/KF5/KParts/kparts/partselectevent.h
/usr/include/KF5/KParts/kparts/plugin.h
/usr/include/KF5/KParts/kparts/readonlypart.h
/usr/include/KF5/KParts/kparts/readwritepart.h
/usr/include/KF5/KParts/kparts/scriptableextension.h
/usr/include/KF5/KParts/kparts/selectorinterface.h
/usr/include/KF5/KParts/kparts/statusbarextension.h
/usr/include/KF5/KParts/kparts/textextension.h
/usr/include/KF5/KParts/kparts/windowargs.h