[gtk/docs-gtk-org] Bump up the build image

[Emmanuele Bassi <ebassi src gnome org>]

commit 8714791a853ccfa4a74e6deb68e8b8d5695c9cf9
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Sat May 14 14:40:21 2022 +0100

    Bump up the build image
    
    The latest image is v38.

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 38e1d4e57a..2a9743b0cd 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -4,7 +4,7 @@ stages:
 
 # Common variables
 variables:
-  FEDORA_IMAGE: "registry.gitlab.gnome.org/gnome/gtk/fedora:v35"
+  FEDORA_IMAGE: "registry.gitlab.gnome.org/gnome/gtk/fedora:v38"
 
 reference:
   image: $FEDORA_IMAGE