[gtk/wip/otte/macos-werror: 2023/2024] CI: turn on -Werror for MacOS build

[Matthias Clasen <matthiasc src gnome org>]

commit 2629f039f3f660a00a101821f858352fb76e68e0
Author: Benjamin Otte <otte redhat com>
Date:   Wed Nov 3 23:35:03 2021 +0100

    CI: turn on -Werror for MacOS build
    
    The build is error-free and we want to keep it that way.
    
    We'd also like to make Timm do real work instead of having to fix clang
    warnings all the time and this build is a clang build.

 .gitlab-ci.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 3f1282ac96..38899c9fee 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -202,7 +202,8 @@ macos:
     - export PATH=/Users/gitlabrunner/Library/Python/3.7/bin:$PATH
     - export MESON_FORCE_BACKTRACE=1
   script:
-    - meson -Dx11-backend=false
+    - meson ${COMMON_MESON_FLAGS}
+            -Dx11-backend=false
             -Dbroadway-backend=true
             -Dmacos-backend=true
             -Dmedia-gstreamer=disabled