[gnome-control-center/wip/hadess/ci-own-image] ci: Use our own gnome-40 image for building

[Bastien Nocera <hadess src gnome org>]

commit c3e833b0f7ee2a047773706a42dd296bfcaa0a57
Author: Bastien Nocera <hadess hadess net>
Date:   Wed Jul 21 18:35:14 2021 +0200

    ci: Use our own gnome-40 image for building
    
    Rather than relying on the image generated by the main development
    branch, mark our own as "-gnome-40" so we can be the ones generating it.

 .gitlab-ci.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 4a2aeed1b..01424790f 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -7,7 +7,8 @@ variables:
   FDO_UPSTREAM_REPO: gnome/gnome-control-center
   # Expiry sets fdo.expires on the image
   FDO_EXPIRES_AFTER: 8w
-  FEDORA_IMAGE: "$CI_REGISTRY/$FDO_UPSTREAM_REPO/fedora/$FDO_DISTRIBUTION_VERSION:$FDO_DISTRIBUTION_TAG"
+  FDO_DISTRIBUTION_TAG: '2021-21-07.1'
+  FEDORA_IMAGE: 
"$CI_REGISTRY/$FDO_UPSTREAM_REPO/fedora/$FDO_DISTRIBUTION_VERSION:$FDO_DISTRIBUTION_TAG-gnome-40"
   # NOTES:
   # - gobject-introspection-devel is needed for gsettings-desktop-schemas
   FEDORA_DEPENDENCIES: >