Purpose: It configures the libdnf5 plugin responsible for invoking systemd inhibitor locks during package management operations (like updates or installations) so power events don’t corrupt your file systems.
I suspect a conflict with some change to libdnf5. Gnome doesn’t seem to have it. What does dnf5 provides /lib/dnf/libdnf5-plugins/00-systemd-inhibit.conf show? Maybe reinstall the package using dnf5 will get a working version.