st: Drop unnecessary gtk header includes

These have survived the code changes that made the
various GTK helpers and enums unused.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2655>

src/st/st-texture-cache.h

@@ -27,7 +27,6 @@
 #endif
 
 #include <gio/gio.h>
-#include <gtk/gtk.h>
 #include <clutter/clutter.h>
 
 #include <st/st-types.h>

src/st/st-theme-node-private.h

@@ -22,8 +22,6 @@
 #ifndef __ST_THEME_NODE_PRIVATE_H__
 #define __ST_THEME_NODE_PRIVATE_H__
 
-#include <gdk/gdk.h>
-
 #include "st-theme-node.h"
 #include "croco/libcroco.h"
 #include "st-types.h"

src/st/st-types.h

@@ -23,7 +23,6 @@
 
 #include <glib-object.h>
 #include <clutter/clutter.h>
-#include <gtk/gtk.h>
 
 G_BEGIN_DECLS
 

src/st/test-theme.c

@@ -28,6 +28,8 @@
 #include <meta-test/meta-context-test.h>
 #include <meta/meta-backend.h>
 
+#include <gtk/gtk.h>
+
 static ClutterActor *stage;
 static StThemeNode *root;
 static StThemeNode *group1;