This is a follow-up to 49599fab564f203b8e92d32e9b28c99e99849bfb.
Fixes: <https://issues.guix.gnu.org/52908>.
* gnu/services/xorg.scm (set-xorg-configuration)[login-manager-service-type]:
When the current system or target system begins with the string "x86_64", use
gdm-service-type as before; otherwise, use sddm-service-type.
* gnu/system/examples/vm-image.tmpl (services): Add sddm-service-type to the
list of service types to remove.
79260c8695