[gegl] ci: Add vala to the prebuilt image

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

commit 3a8ebd128c1ddb8f3311790a2873a28aa82e9adb
Author: Jan Vesely <jano vesely gmail com>
Date:   Tue Jun 2 11:05:05 2020 -0400

    ci: Add vala to the prebuilt image
    
    vala is installed in both babl and gegl steps
    Signed-off-by: Jan Vesely <jano vesely gmail com>

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index de181310c..303e41866 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -28,7 +28,7 @@ build-image:
     - mkdir -p /kaniko/.docker
     - echo 
"{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" 
> /kaniko/.docker/config.json
     - echo "FROM archlinux/base:latest" > Dockerfile
-    - echo "RUN pacman -Syu --noconfirm --needed git base-devel ccache meson lcms2 gobject-introspection 
pacman-contrib && pacman -Scc --noconfirm " >> Dockerfile
+    - echo "RUN pacman -Syu --noconfirm --needed git base-devel ccache meson lcms2 gobject-introspection 
pacman-contrib vala && pacman -Scc --noconfirm " >> Dockerfile
 
     - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/Dockerfile --destination 
$CI_REGISTRY_IMAGE:ci-latest --cache=true --cache-ttl=120h