/usr/lib/systemd/user/ is in update-notifier 3.192.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/systemd/user/graphical-session.target.wants/
/usr/lib/systemd/user/graphical-session.target.wants/unicast-local-avahi.path
/usr/lib/systemd/user/graphical-session.target.wants/update-notifier-crash.path
/usr/lib/systemd/user/graphical-session.target.wants/update-notifier-release.path
/usr/lib/systemd/user/unicast-local-avahi.path
/usr/lib/systemd/user/unicast-local-avahi.service
/usr/lib/systemd/user/update-notifier-crash.path
/usr/lib/systemd/user/update-notifier-crash.service
/usr/lib/systemd/user/update-notifier-livepatch.path
/usr/lib/systemd/user/update-notifier-livepatch.service
/usr/lib/systemd/user/update-notifier-release.path
/usr/lib/systemd/user/update-notifier-release.service