Fix draw manager F12 evaluation mode

This effectively allows for ob duplicator_render/viewport to work properly
when doing final renders.

source/blender/draw/intern/draw_manager.c

@@ -3609,6 +3609,7 @@ void DRW_render_to_image(RenderEngine *re, struct Depsgraph *depsgraph)
 	/* Reset before using it. */
 	memset(&DST, 0x0, sizeof(DST));
 	DST.options.is_image_render = true;
+	DST.options.is_scene_render = true;
 	DST.options.draw_background = scene->r.alphamode == R_ADDSKY;
 
 	DST.draw_ctx = (DRWContextState){