fix: DataGridCell corner radius resource reference.

src/Shared/HandyControl_Shared/Themes/Theme.xaml

@@ -1,4 +1,4 @@
-<!--
+<!--
     This code was generated by a tool.
 
     Changes to this file may cause incorrect behavior and will be lost if
@@ -14552,4 +14552,4 @@
 	</Style>
 	<Style BasedOn="{StaticResource RangeSliderBaseStyle}" TargetType="hc:RangeSlider" />
 	<Style BasedOn="{StaticResource SliderBaseStyle}" TargetType="Slider" />
-</ResourceDictionary>
+</ResourceDictionary>