dbus: remove SystemdService from D-Bus service files

.gear/ximper-shell-notification-center.spec

@@ -53,7 +53,6 @@ A component of the Ximper Shell.
 %_bindir/%name
 %_bindir/%name-client
 
-%_userunitdir/%name.service
 %_datadir/dbus-1/services/%xdg_name.service
 %_datadir/dbus-1/services/%xdg_name.cc.service
 %_datadir/glib-2.0/schemas/%xdg_name.gschema.xml

meson_options.txt

-option('systemd-service', type: 'boolean', value: true, description: 'Install systemd user service unit.')
+option('systemd-service', type: 'boolean', value: false, description: 'Install systemd user service unit.')
 option('pulse-audio', type: 'boolean', value: true, description: 'Provide PulseAudio Widget.')
 option('ddc', type: 'boolean', value: true, description: 'Provide DDC/CI monitor brightness control via libddcutil.')
 option('man-pages', type: 'boolean', value: true, description: 'Install all man pages.')

services/dbus/ru.ximperlinux.shell.NotificationCenter.cc.service.in

 [D-BUS Service]
 Name=ru.ximperlinux.shell.NotificationCenter
 Exec=@bindir@/ximper-shell-notification-center
-SystemdService=ximper-shell-notification-center.service

services/dbus/ru.ximperlinux.shell.NotificationCenter.service.in

 [D-BUS Service]
 Name=org.freedesktop.Notifications
 Exec=@bindir@/ximper-shell-notification-center
-SystemdService=ximper-shell-notification-center.service