Simplify line assignment in CoreLineSeries class

Removed unnecessary .ToArray() call in line assignment within the
CoreLineSeries class. This change avoids creating an array,
potentially improving performance and allowing the data to be
handled in its original enumerable or collection form.

src/LiveChartsCore/CoreLineSeries.cs

@@ -186,7 +186,7 @@ public override void Invalidate(Chart<TDrawingContext> chart)
             var isSegmentEmpty = true;
             VectorManager<CubicBezierSegment, TDrawingContext>? strokeVector = null, fillVector = null;
 
-            var line = GetSpline(segment, stacker).ToArray();
+            var line = GetSpline(segment, stacker);
 
             foreach (var data in line)
             {