[gtkmm-documentation/kjellahl/testci] CI: More docbook-style-xsl

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 6fc4f0f149bc33eedeaa69c20e0c56beb674a970
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Sun Jan 9 11:48:50 2022 +0100

    CI: More docbook-style-xsl

 .gitlab-ci.yml | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 392bc30..e264afe 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -43,6 +43,7 @@ html-tutorial:
     FEDORA_DEPS:
       gcc
       gcc-c++
+      docbook-style-xsl
       libxslt
       ninja-build
       python3