Can these focusable setter calls be removed?

[jessegreenberg]

I think the implementation for the soccer balls makes the group focusable and manually redraws custom focus highlights. I don't think the soccer balls themselves are focusable, should these lines be removed?

Noticed while working on phetsims/scenery#1558

Subject: [PATCH] Fix bug with images and other forms
---
Index: js/view/SoccerBallNode.ts
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/js/view/SoccerBallNode.ts b/js/view/SoccerBallNode.ts
--- a/js/view/SoccerBallNode.ts	(revision 029a4154a7621a9da818652a43dfceef7c0b5600)
+++ b/js/view/SoccerBallNode.ts	(date 1694814157805)
@@ -159,7 +159,7 @@
     } );
 
     soccerBall.resetEmitter.addListener( () => {
-      this.focusable = false;
+      // this.focusable = false;
       this.pickable = false;
       this.mouseArea = Shape.rectangle( 0, 0, 0, 0 );
       this.touchArea = Shape.rectangle( 0, 0, 0, 0 );
@@ -168,7 +168,7 @@
     this.addLinkedElement( soccerBall );
 
     // Not focusable until the ball has been kicked into the play area
-    this.focusable = false;
+    // this.focusable = false;
 
     super.addDebugText( soccerBall );
   }

[jessegreenberg]

Also just noticed this line in SoccerBallNode and thought it might be out of date:

Uses AccessibleSlider so that the soccer ball functions similarly to a slider in alternativeInput.

[marlitas]

Thanks @jessegreenberg. You are correct. That code is now vestigial. I removed the usages of focusable and updated the documentation.