Do not inherit TextDecorations in popup (#20472)

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

@@ -7,6 +7,7 @@
     <Setter Property="FontFamily" Value="{DynamicResource ContentControlThemeFontFamily}" />
     <Setter Property="FontWeight" Value="Normal" />
     <Setter Property="FontStyle" Value="Normal" />
+    <Setter Property="Inline.TextDecorations" Value="" />
     <Setter Property="Template">
       <ControlTemplate>
         <LayoutTransformControl LayoutTransform="{TemplateBinding Transform}">

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

@@ -9,6 +9,7 @@
     <Setter Property="FontFamily" Value="{DynamicResource ContentControlThemeFontFamily}" />
     <Setter Property="FontWeight" Value="Normal" />
     <Setter Property="FontStyle" Value="Normal" />
+    <Setter Property="Inline.TextDecorations" Value="" />
     <Setter Property="Template">
       <ControlTemplate>
         <LayoutTransformControl LayoutTransform="{TemplateBinding Transform}">

src/Avalonia.Themes.Simple/Controls/OverlayPopupHost.xaml

@@ -6,6 +6,9 @@
     <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}" />
     <Setter Property="FontSize" Value="{DynamicResource FontSizeNormal}" />
     <Setter Property="FontFamily" Value="{DynamicResource ContentControlThemeFontFamily}" />
+    <Setter Property="FontWeight" Value="Normal" />
+    <Setter Property="FontStyle" Value="Normal" />
+    <Setter Property="Inline.TextDecorations" Value="" />
     <Setter Property="Template">
       <ControlTemplate>
         <!--  Do not forget to update Templated_Control_With_Popup_In_Template_Should_Set_TemplatedParent test  -->

src/Avalonia.Themes.Simple/Controls/PopupRoot.xaml

@@ -8,6 +8,9 @@
     <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}" />
     <Setter Property="FontSize" Value="{DynamicResource FontSizeNormal}" />
     <Setter Property="FontFamily" Value="{DynamicResource ContentControlThemeFontFamily}" />
+    <Setter Property="FontWeight" Value="Normal" />
+    <Setter Property="FontStyle" Value="Normal" />
+    <Setter Property="Inline.TextDecorations" Value="" />
     <Setter Property="Template">
       <ControlTemplate>
         <LayoutTransformControl LayoutTransform="{TemplateBinding Transform}">