[libpanel] build: bump GTK required version

[Christian Hergert <chergert src gnome org>]

commit b2daca3149c44e2bbaacad6bdb4d5f2609c43c83
Author: Christian Hergert <chergert redhat com>
Date:   Wed Jul 27 11:48:27 2022 -0700

    build: bump GTK required version

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index b12ec43..e5aca02 100644
--- a/meson.build
+++ b/meson.build
@@ -27,7 +27,7 @@ vapidir = join_paths(datadir, 'vala', 'vapi')
 
 # Check dependencies
 glib_req_version = '2.72'
-gtk_req_version = '4.3'
+gtk_req_version = '4.7'
 adwaita_req_version = '1.0'
 
 glib_req = '>= @0@'.format(glib_req_version)