[mutter] ci: Run tests with 10 Hz dummy monitors

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit e8ace922a2131d2920cb79c1a0404f2bc2542e2b
Author: Jonas Ådahl <jadahl gmail com>
Date:   Mon Nov 9 09:34:09 2020 +0100

    ci: Run tests with 10 Hz dummy monitors
    
    This decreases flakyness of some tests when runners are under heavy
    load.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1555

 .gitlab-ci/run-tests.sh | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/.gitlab-ci/run-tests.sh b/.gitlab-ci/run-tests.sh
index dc77342b98..63726d1171 100755
--- a/.gitlab-ci/run-tests.sh
+++ b/.gitlab-ci/run-tests.sh
@@ -7,6 +7,8 @@ dconf update
 mkdir -m 700 $XDG_RUNTIME_DIR
 glib-compile-schemas $GSETTINGS_SCHEMA_DIR
 
+export MUTTER_DEBUG_DUMMY_MODE_SPECS="800x600@10.0"
+
 dbus-run-session -- \
     xvfb-run -s '+iglx -noreset' \
         meson test -C build --no-rebuild -t 10 --wrap catchsegv