Update Systemd security settings

As part of https://fedoraproject.org/wiki/Changes/SystemdSecurityHardening which has been approved for Fedora 40, I am working on updating Systemd services to add additional hardening settings, please review this PR and let me know if you have any feedback.

https://www.freedesktop.org/software/systemd/man/latest/systemd.exec.html has detailed information on each of these settings including the version of Systemd where they were introduced.