- Remove unnecessary Requires(post*)

- Config file changes:
* No longer own sddm.conf. The migration for this conflicts with
the other migration code, so:
* Drop code for migrating from Current=maui (Leap <= 42.2)
and the monolithic /etc/sddm.conf (Leap <= 42.3)

- Add patch and drop unnecessary BuildRequirements of
extra-cmake-modules and kf5-filesystem:
* 0001-Drop-unnecessary-ECM-dependency-and-dead-uninstall-t.patch
- Split the greeter into a subpackage and use _multibuild to build
both daemon and greeter for Qt 5 and Qt 6. Add patches to allow
for greeter coinstallation:
* 0002-Make-sddm-greeter-for-Qt-5-and-Qt-6-coinstallable.patch
* 0003-Let-themes-specify-the-used-version-of-Qt.patch
- Refresh 0001-Read-the-DISPLAYMANAGER_AUTOLOGIN-value-from-sysconf.patch
- Don't set CMAKE_BUILD_TYPE=Release
- Make branding packages noarch
- Add %check

- Add patches to allow dropping InputMethod= from 11-kwin_wayland.conf
(boo#1212880):
* 0001-greeter-Look-at-WAYLAND_DISPLAY-for-platform-detecti.patch
* 0002-Ignore-InputMethod-qtvirtualkeyboard-on-wayland.patch

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

- Update to 0.20.0: