Depsgraph: Pass bmain to depsgraph object creation

Currently unused, but will allow to keep of an owner of the depsgraph.

Could also simplify other APIs in the future by avoiding to pass bmain
explicitly to relation update functions and things like that.

source/blender/python/gpu/gpu_py_offscreen.c

@@ -32,6 +32,7 @@
 
 #include "BLI_utildefines.h"
 
+#include "BKE_global.h"
 #include "BKE_library.h"
 #include "BKE_scene.h"
 
@@ -238,7 +239,7 @@ static PyObject *bpygpu_offscreen_draw_view3d(BPyGPUOffScreen *self,
 
   BLI_assert(BKE_id_is_in_global_main(&scene->id));
 
-  depsgraph = BKE_scene_get_depsgraph(scene, view_layer, true);
+  depsgraph = BKE_scene_get_depsgraph(G_MAIN, scene, view_layer, true);
 
   rv3d_mats = ED_view3d_mats_rv3d_backup(ar->regiondata);