[glibmm/glibmm-2-70] CI: Accept warnings from clang++

[Kjell Ahlstedt <kjellahl src gnome org>]

commit fe7dad534fd69b2bd2cce48423540459f76a6f1b
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Wed May 4 15:08:01 2022 +0200

    CI: Accept warnings from clang++

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f8c1902f..7124ed77 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -164,7 +164,7 @@ release_clang_build:
     - ninja -C libsigc/_build install
     - mkdir _build && cd _build
     # -Ddebug=false + -Doptimization=3 correspond to -Dbuildtype=release
-    - CC=clang CXX=clang++ meson --prefix=/usr --libdir=lib -Ddebug=false -Doptimization=3 -Dwarnings=fatal
+    - CC=clang CXX=clang++ meson --prefix=/usr --libdir=lib -Ddebug=false -Doptimization=3 -Dwarnings=max
     - meson compile
     - meson test
     - meson install