Add flatpak CI support

.flatpak-manifest.json

@@ -2,12 +2,12 @@
     "id": "org.kde.konsole",
     "branch": "master",
     "runtime": "org.kde.Platform",
-    "runtime-version": "5.15-22.08",
+    "runtime-version": "6.6-kf6preview",
     "sdk": "org.kde.Sdk",
     "command": "konsole",
     "tags": ["nightly"],
     "desktop-file-name-suffix": " (Nightly)",
-    "finish-args": ["--share=ipc", "--socket=x11", "--socket=wayland", "--talk-name=org.freedesktop.Flatpak" ],
+    "finish-args": ["--share=ipc", "--socket=fallback-x11", "--socket=wayland", "--talk-name=org.freedesktop.Flatpak" ],
 
     "modules": [
         {

.gitlab-ci.yml

@@ -8,5 +8,5 @@ include:
       - /gitlab-templates/linux-qt6.yml
       - /gitlab-templates/freebsd-qt6.yml
       - /gitlab-templates/windows-qt6.yml
-    #  - https://invent.kde.org/sysadmin/ci-utilities/raw/master/gitlab-templates/flatpak.yml
+      - /gitlab-templates/flatpak.yml
       - /gitlab-templates/craft-windows-x86-64-qt6.yml