/usr/share/kservices5/ is in plasma-widgets-addons 4:5.5.5-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/kservices5/plasma-applet-org.kde.plasma.activitypager.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.calculator.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.colorpicker.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.comic.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.diskquota.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.fifteenpuzzle.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.fuzzyclock.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.kickerdash.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.kimpanel.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.konsoleprofiles.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.notes.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.quicklaunch.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.showdesktop.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.systemloadviewer.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.timer.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.userswitcher.desktop
/usr/share/kservices5/plasma-applet-org.kde.plasma.webbrowser.desktop