Comment # 24 on bug 1215987 from Felix Miata

On host g5eas on both TW and Slowroll, I used update-alternatives to switch
from sddm to xdm, and both as expected launched startplasma-x11 on vt7.
Afterward on Slowroll, I uninstalled sddm and rebooted to find xdm still
launches startplasma-x11:
# inxi -Cz
CPU:
  Info: single core model: Intel Pentium 4 bits: 64 type: MT cache: L2: 2 MiB
  Speed (MHz): avg: 3200 min/max: N/A cores: 1: 3200 2: 3200
# inxi -GSaz
System:
  Kernel: 6.6.23-1-longterm arch: x86_64 bits: 64 compiler: gcc v: 13.2.1
    clocksource: tsc avail: hpet,acpi_pm parameters: root=LABEL=m25p19sslo
    ipv6.disable=1 net.ifnames=0 noresume consoleblank=0 mitigations=off
  Desktop: KDE Plasma v: 5.27.10 tk: Qt v: 5.15.12 info: frameworks
    v: 5.115.0 wm: kwin_x11 vt: 7 dm: XDM Distro: openSUSE Tumbleweed-Slowroll
    20240213
Graphics:
  Device-1: XGI Z7/Z9 vendor: Gigabyte driver: N/A bus-ID: 0a:03.0
    chip-ID: 18ca:0020 class-ID: 0300
  Device-2: NVIDIA G98 [GeForce 8400 GS Rev. 2] vendor: PNY driver: nouveau
    v: kernel non-free: series: 340.xx status: legacy (EOL~2019-12-xx) last:
    release: 340.108 kernel: 5.4 xorg: 1.20 arch: Tesla process: 40-80nm
    built: 2006-2013 pcie: gen: 1 speed: 2.5 GT/s lanes: 1 link-max: lanes: 16
    ports: active: DVI-I-1,VGA-1 empty: none bus-ID: 0b:00.0
    chip-ID: 10de:06e4 class-ID: 0300
  Display: x11 server: X.Org v: 21.1.11 compositor: kwin_x11 driver: X:
    loaded: modesetting unloaded: fbdev,vesa alternate: nouveau,nv,nvidia
    dri: nouveau gpu: nouveau display-ID: :0 screens: 1
  Screen-1: 0 s-res: 3600x1200 s-dpi: 120 s-size: 762x254mm (30.00x10.00")
    s-diag: 803mm (31.62")
  Monitor-1: DVI-I-1 pos: primary,left model: NEC EA243WM serial: <filter>
    built: 2011 res: 1920x1200 hz: 60 dpi: 94 gamma: 1.2
    size: 519x324mm (20.43x12.76") diag: 612mm (24.1") ratio: 16:10 modes:
    max: 1920x1200 min: 640x480
  Monitor-2: VGA-1 pos: right model: Dell P2213 serial: <filter> built: 2012
    res: 1680x1050 hz: 60 dpi: 90 gamma: 1.2 size: 473x296mm (18.62x11.65")
    diag: 558mm (22") ratio: 16:10 modes: max: 1680x1050 min: 720x400
  API: EGL v: 1.5 hw: drv: nvidia nouveau platforms: device: 0 egl: 1.4
    drv: nouveau device: 1 drv: swrast gbm: egl: 1.4 drv: nouveau surfaceless:
    egl: 1.4 drv: nouveau x11: egl: 1.4 drv: nouveau inactive: wayland
  API: OpenGL v: 4.5 compat-v: 3.3 vendor: mesa v: 23.3.6 glx-v: 1.4
    direct-render: yes renderer: NV98 device-ID: 10de:06e4 memory: 483.4 MiB
    unified: no

I need to get back to comment #0 host to retest.