Restore PathIcon Foreground setter in Fluent theme (#12789)

* Restore PathIcon Foreground setter in Fluent theme

* Use TextControlForeground resource

src/Avalonia.Themes.Fluent/Controls/PathIcon.xaml

@@ -10,6 +10,7 @@
     </StackPanel>
   </Design.PreviewWith>
   <ControlTheme x:Key="{x:Type PathIcon}" TargetType="PathIcon">
+    <Setter Property="Foreground" Value="{DynamicResource TextControlForeground}" />
     <Setter Property="Background" Value="Transparent" />
     <Setter Property="Height" Value="{DynamicResource IconElementThemeHeight}" />
     <Setter Property="Width" Value="{DynamicResource IconElementThemeWidth}" />