I did some tests using the git version some time ago.
Let's see what happens? openQA will probably need adjustments for
the VT change.

- Add patch to fix parsing some session .desktop files:
* 0001-Session-Parse-.desktop-files-manually-again.patch

- Update to 0.20.0:
+ Initial Qt6 support (Will break themes which rely on Qt 5)
+ **Experimental** support for running the greeter with Wayland
+ Enable HiDPI scaling by default
+ Support for running X11 display server without root privileges
+ Greeter: Support setting environment variables
+ Allow additional env vars to be defined in session files (#1370)
+ Make accountsservice data directory overridable via CMake
+ Add support for X11 cursor size configuration
+ Search XDG Base Directories for session files
+ Display information and errors from PAM in the greeter (#1486)
* Remove the Passwd backend, make PAM mandatory
* Bump minimum CMake version to 3.4
* Introduce SDDM_INITIAL_VT as the TTY to reach out to
* Set XCURSOR_SIZE in XorgDisplayServer::start
* Make it possible to start ConsoleKit D-Bus service during SDDM startup
* pam: Do not use tally2 if faillock is present
* Bump to Qt 5.15, port away from deprecated APIs
* remove `-logfile` arg that causes server to fail
- Set RUNTIME_DIR to /run/sddm when using systemd to follow FHS 3.0
- Use avatars in FacesDir first and if not found search other locations
- Switch to using libxau with `FamilyWild` (#1230)
- New interface to access config values from themes (#1097)
- Session names are translated now (#1645)
- Many more bugfixes
- Important change: SDDM now uses the first free VT, it no longer prefers
tty7 (the InitialVT option in 00-general.conf has no effect anymore)