[gtk] build: Set version to 4.7

[Matthias Clasen <matthiasc src gnome org>]

commit d1102f586c1664b759b7dfb1f6f1384cea19c0fe
Author: Benjamin Otte <otte redhat com>
Date:   Mon Feb 14 00:28:21 2022 +0100

    build: Set version to 4.7

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 63b4d73bfe..e940de27ca 100644
--- a/meson.build
+++ b/meson.build
@@ -1,5 +1,5 @@
 project('gtk', 'c',
-        version: '4.6.1',
+        version: '4.7.0',
         default_options: [
           'buildtype=debugoptimized',
           'warning_level=1',