[gtksourceview] build: remove unused GtkSourceBindingGroup

[Christian Hergert <chergert src gnome org>]

commit 313400b43b2223947b1b832fb37a01c745592309
Author: Christian Hergert <chergert redhat com>
Date:   Tue Sep 6 12:31:02 2022 -0700

    build: remove unused GtkSourceBindingGroup
    
    This isn't used anymore, and we won't need it as we have GBindingGroup
    upstream in GLib now.

 gtksourceview/gtksourcebindinggroup-private.h |  59 ---
 gtksourceview/gtksourcebindinggroup.c         | 623 --------------------------
 gtksourceview/gtksourcecompletion.c           |   1 -
 gtksourceview/meson.build                     |   1 -
 4 files changed, 684 deletions(-)
---
diff --git a/gtksourceview/gtksourcecompletion.c b/gtksourceview/gtksourcecompletion.c
index dc9862ac..b8c5ac5a 100644
--- a/gtksourceview/gtksourcecompletion.c
+++ b/gtksourceview/gtksourcecompletion.c
@@ -24,7 +24,6 @@
 
 #include "config.h"
 
-#include "gtksourcebindinggroup-private.h"
 #include "gtksourcecompletion-private.h"
 #include "gtksourcecompletioncontext-private.h"
 #include "gtksourcecompletionlist-private.h"
diff --git a/gtksourceview/meson.build b/gtksourceview/meson.build
index 279d1099..61b9b7b5 100644
--- a/gtksourceview/meson.build
+++ b/gtksourceview/meson.build
@@ -113,7 +113,6 @@ core_public_c = files([
 core_private_c = files([
   'gtksourceassistant.c',
   'gtksourceassistantchild.c',
-  'gtksourcebindinggroup.c',
   'gtksourcebufferinputstream.c',
   'gtksourcebufferinternal.c',
   'gtksourcebufferoutputstream.c',