Fix code related warnings

src/Avalonia.Base/StyledElement.cs

@@ -81,7 +81,7 @@ namespace Avalonia
                 defaultValue: ThemeVariant.Light);
 
         /// <summary>
-        /// Defines the <see cref="RequestedThemeVariant"/> property.
+        /// Defines the RequestedThemeVariant property.
         /// </summary>
         public static readonly StyledProperty<ThemeVariant?> RequestedThemeVariantProperty =
             AvaloniaProperty.Register<StyledElement, ThemeVariant?>(

src/Avalonia.Controls/Application.cs

@@ -95,7 +95,7 @@ namespace Avalonia
             set => SetValue(RequestedThemeVariantProperty, value);
         }
         
-        /// <inheritdoc cref="ThemeVariantScope.ActualThemeVariant"/>
+        /// <inheritdoc cref="StyledElement.ActualThemeVariant"/>
         public ThemeVariant ActualThemeVariant
         {
             get => GetValue(ActualThemeVariantProperty);