[pango/pango2] ci: Use the right option

[Matthias Clasen <matthiasc src gnome org>]

commit fefa46cb1b2c881d9cd772f2c31285db619337b1
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Jun 14 21:27:49 2022 -0400

    ci: Use the right option

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index a55a95f2..12427eb2 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -118,7 +118,7 @@ reference:
   variables:
     EXTRA_MESON_FLAGS: ""
   script:
-    - meson ${COMMON_MESON_FLAGS} ${EXTRA_MESON_FLAGS} -Dgtk_doc=true _build
+    - meson ${COMMON_MESON_FLAGS} ${EXTRA_MESON_FLAGS} -Ddocumentation=true _build
     - ninja -C _build
     - mkdir -p _reference/
     - mv _build/docs/Pango/ _reference/