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

[Bartłomiej Piotrowski <bpiotrowski src gnome org>]

commit 5232e010c1a91f97b17aa403cc09cfcc01e8d8b2
Author: Bartłomiej Piotrowski <b bpiotrowski pl>
Date:   Wed Jul 27 12:42:49 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 fd5937b..91e2397 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -5,7 +5,6 @@ stages:
     - cross_environment
 
 flatpak:
-    image: registry.gitlab.gnome.org/gnome/gnome-runtime-images/gnome:master
     stage: test
     variables:
         MANIFEST_PATH: "build-aux/flatpak/org.gnome.Characters.json"