[babl] build: attempt forcing of older glibc to unbreak CI

[Øyvind "pippin" Kolås <ok src gnome org>]

commit 2d4c629c63b3e211b1036f9f462ec03fe164c441
Author: Øyvind Kolås <pippin gimp org>
Date:   Thu Feb 18 20:36:12 2021 +0100

    build: attempt forcing of older glibc to unbreak CI

 .gitlab-ci.yml | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f98bb7b71..8a7637b08 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -12,6 +12,7 @@ cache:
     paths:
       - _build/meson-logs
   before_script:
+    - pacman -Su --noconfirm https://archive.archlinux.org/packages/g/glibc/glibc-2.33-3-x86_64.pkg.tar.zst
     - pacman -Syu --noconfirm --needed --cachedir $PACMAN_CACHE
         base-devel
         git