Switch the gtk-doc subproject to the gtk-doc-for-gtk4 branch

This branch contains assorted fixes and enhancements that
are needed to build the gtk4 docs.

diff --git a/subprojects/gtk-doc.wrap b/subprojects/gtk-doc.wrap
index 7469d027b06c71e057272011f4f3bc6b5c7b3cf5..0b8d4412d074dbc5d22c888e21050e169887d48d 100644 (file)
--- a/subprojects/gtk-doc.wrap
+++ b/subprojects/gtk-doc.wrap
@@ -1,4 +1,4 @@
 [wrap-git]
 directory=gtk-doc
 url=https://gitlab.gnome.org/GNOME/gtk-doc.git
-revision=master
+revision=gtk-doc-for-gtk4