fix: laser pointer trail disappearing on pointerup (#9413) (#9427)

* Fix laser pointer trail disappearing on pointerup (#9413)

Previously, the laser pointer trail would disappear as soon as the pointerup event was triggered. This fix delays the trail removal to ensure it persists for a smoother visual experience.

Fixes #9413.

* Remove extra blank lines

Minor formatting cleanup. No functional changes.

packages/excalidraw/animated-trail.ts

@@ -129,7 +129,6 @@ export class AnimatedTrail implements Trail {
   }
 
   private update() {
-    this.pastTrails = [];
     this.start();
     if (this.trailAnimation) {
       this.trailAnimation.setAttribute("begin", "indefinite");