Enable antialiasing for PushGeometryClip

src/Skia/Avalonia.Skia/DrawingContextImpl.cs

@@ -506,7 +506,7 @@ namespace Avalonia.Skia
         public void PushGeometryClip(IGeometryImpl clip)
         {
             Canvas.Save();
-            Canvas.ClipPath(((GeometryImpl)clip).EffectivePath);
+            Canvas.ClipPath(((GeometryImpl)clip).EffectivePath, SKClipOperation.Intersect, true);
         }
 
         /// <inheritdoc />

src/Windows/Avalonia.Direct2D1/Media/DrawingContextImpl.cs

@@ -541,7 +541,8 @@ namespace Avalonia.Direct2D1.Media
                 ContentBounds = PrimitiveExtensions.RectangleInfinite,
                 MaskTransform = PrimitiveExtensions.Matrix3x2Identity,
                 Opacity = 1,
-                GeometricMask = ((GeometryImpl)clip).Geometry
+                GeometricMask = ((GeometryImpl)clip).Geometry,
+                MaskAntialiasMode = AntialiasMode.PerPrimitive
             };
             var layer = _layerPool.Count != 0 ? _layerPool.Pop() : new Layer(_deviceContext);
             _deviceContext.PushLayer(ref parameters, layer);