[gnome-settings-daemon] ci: Install libXfixes-devel

[Benjamin Berg <bberg src gnome org>]

commit 36127697182e56a2d8f86dbc63dd8af2f3abd581
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Fri Jul 16 11:18:58 2021 +0200

    ci: Install libXfixes-devel
    
    libXfixes 6.0 provides the new ClientDisconnectMode that clients can
    use to declare themselves as to-be-terminated.

 .gitlab-ci.yml | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index a579d7ac..f7deb597 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -38,6 +38,7 @@ variables:
     libX11-devel
     libXi-devel
     libXtst-devel
+    libXfixes-devel
     llvm
     mesa-dri-drivers
     meson