[gtk/macos-ci] disable pixman tests

[Matthias Clasen <matthiasc src gnome org>]

commit 9859191573fd59e3dc5e1a949cc0f100d6ff3504
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Jan 3 13:23:45 2021 -0500

    disable pixman tests

 .gitlab-ci.yml | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 770e9162c3..c52a26c6c9 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -158,6 +158,7 @@ macos:
     - meson -Dx11-backend=false
             -Dintrospection=disabled
             -Dcpp_std=c++11
+            -Dpixman:tests=disabled
             _build
     - ninja -C _build
   artifacts: