Drop dependency on pkexec
Based on discussion on fedora-devel[0][1] as well as #1604 (closed), drop the use of pkexec. pkexec was used only for starting / stopping / enabling / disabling the sshd service via systemd[2] (via dbus).
This changes the org.gnome.controlcenter.remote-login-helper
policy to
request the necessary systemd permissions, and changes to using polkit
to request the permission, then making the dbus calls once the
permission is acquired.