Dead code in Slider.ts

[pixelzoom]

@jonathanolson add line 476 in https://github.com/phetsims/sun/commit/d8eaa561bc076cb517d62fa72e70aa530b28a64e, but commented it out. Why?

    // must be after the button is instrumented
476 // assert && assert( !this.isPhetioInstrumented() || this.enabledRangeProperty.isPhetioInstrumented() );
    !ownsEnabledRangeProperty && this.enabledRangeProperty instanceof Property && this.addLinkedElement( this.enabledRangeProperty, {
      tandem: options.tandem.createTandem( 'enabledRangeProperty' )
    } );