Fix rounding error in Clip Content

Rounds the position and size of the final clip rect to avoid flickering issues.

Fixes https://github.com/godotengine/godot/issues/46493

servers/rendering/renderer_canvas_cull.cpp

@@ -148,6 +148,8 @@ void RendererCanvasCull::_cull_canvas_item(Item *p_canvas_item, const Transform2
 		} else {
 			ci->final_clip_rect = global_rect;
 		}
+		ci->final_clip_rect.position = ci->final_clip_rect.position.round();
+		ci->final_clip_rect.size = ci->final_clip_rect.size.round();
 		ci->final_clip_owner = ci;
 
 	} else {