Allow reading /run/systemd/sessions/
Several applications use it now that utmp and wtmp are being removed because they are not Y2038 compliant
This is the case for example in openSUSE Tumbleweed and openSUSE MicroOS: https://microos.opensuse.org/blog/2023-11-06-utmp-and-wtmp-are-gone/
Closes #360 (closed)