feat(Native): Address Rule CA1823

src/Avalonia.Native/IAvnMenu.cs

@@ -46,7 +46,6 @@ namespace Avalonia.Native.Interop.Impl
         private AvaloniaNativeMenuExporter _exporter;
         private List<__MicroComIAvnMenuItemProxy> _menuItems = new List<__MicroComIAvnMenuItemProxy>();
         private Dictionary<NativeMenuItemBase, __MicroComIAvnMenuItemProxy> _menuItemLookup = new Dictionary<NativeMenuItemBase, __MicroComIAvnMenuItemProxy>();
-        private CompositeDisposable _propertyDisposables = new CompositeDisposable();
 
         public void RaiseNeedsUpdate()
         {

src/Avalonia.Native/WindowImplBase.cs

@@ -63,7 +63,6 @@ namespace Avalonia.Native
         private double _savedScaling;
         private GlPlatformSurface _glSurface;
         private NativeControlHostImpl _nativeControlHost;
-        private IGlContext _glContext;
 
         internal WindowBaseImpl(IAvaloniaNativeFactory factory, AvaloniaNativePlatformOptions opts,
             AvaloniaNativeGlPlatformGraphics glFeature)