[gnome-shell] ci: Update mutter image

[Marge Bot <marge-bot src gnome org>]

commit 508442cef27b463501e193f58f9a4c448c82f0b5
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Aug 12 20:59:31 2021 +0200

    ci: Update mutter image
    
    Mutter now requires a development version of glib, so bump the
    image to satisfy the dependency.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1947>

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 8a07493b11..8ed0255956 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -31,7 +31,7 @@ variables:
     LINT_LOG: "eslint-report.xml"
     LINT_MR_LOG: "eslint-mr-report.xml"
 
-image: registry.gitlab.gnome.org/gnome/mutter/fedora/34:x86_64-2021-07-22.0
+image: registry.gitlab.gnome.org/gnome/mutter/fedora/34:x86_64-2021-08-01.0
 
 workflow:
     rules: