[gnome-sudoku/barthalion/gnome-runtime-images-quay] Update (or drop) the Docker image used by Flatpak job

[Bartłomiej Piotrowski <bpiotrowski src gnome org>]

commit 7fd0e5d5b9f4e8995c86693f52e526c2eeebea0e
Author: Bartłomiej Piotrowski <b bpiotrowski pl>
Date:   Wed Jul 27 12:46:52 2022 +0200

    Update (or drop) the Docker image used by Flatpak job
    
    The gnome-runtime-images have been recently migrated to Quay. This is already reflected in the template.
    
    Please note this MR has been created semi-automatically. If it doesn't make sense, feel free to close it.

 .gitlab-ci.yml | 1 -
 1 file changed, 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 32e59f6..1343c7a 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -4,7 +4,6 @@ variables:
     BUNDLE: "sudoku-dev.flatpak"
 
 flatpak:
-    image: 'registry.gitlab.gnome.org/gnome/gnome-runtime-images/gnome:master'
     variables:
         MANIFEST_PATH: " build-aux/org.gnome.Sudoku.json"
         FLATPAK_MODULE: "gnome-sudoku"