CurvePath: Use correct line type in `closePath()`. (#26850)

* fix #26849

* Update CurvePath.js

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Co-authored-by: Michael Herzog <[email protected]>

src/extras/core/CurvePath.js

@@ -33,7 +33,8 @@ class CurvePath extends Curve {
 
 		if ( ! startPoint.equals( endPoint ) ) {
 
-			this.curves.push( new Curves[ 'LineCurve' ]( endPoint, startPoint ) );
+			const lineType = ( startPoint.isVector2 === true ) ? 'LineCurve' : 'LineCurve3';
+			this.curves.push( new Curves[ lineType ]( endPoint, startPoint ) );
 
 		}