Fix undo bug returning to drawing a Pen tool rubber-band curve on prior parts of a previously drawn shape (#2710)

fix: add cleanup after pen path is closed

Co-authored-by: Keavon Chambers <keavon@keavon.com>

editor/src/messages/tool/tool_messages/pen_tool.rs

@@ -706,6 +706,7 @@ impl PenToolData {
 					layer,
 					modification_type: VectorModificationType::SetG1Continuous { handles, enabled: colinear },
 				});
+				self.cleanup(responses);
 			}
 		}