windowManager: Remove timeout on starting X11 services
With Xwayland started on demand, mutter/gnome-shell will spawn Xwayland and GNOME settings daemon Xsettings.
Currently, gnome-shell uses a timeout of 5 seconds before canceling the launch and declare failure to start X11 services.
While 5 seconds may seem like a lot of time, when this is executed on a virtual machine part of a QA tests under load, this causes random failures.
There is no good value here, we could increase the timeout but it will always remain racy. Instead, remove the timeout, systemd itself already has a timeout mechanism (with a much longer wait time).