Workaround for unexpected CS0419 after enabling GenerateDocumentationFile

Author: Arlodotexe

Directory.Build.props

@@ -29,8 +29,11 @@
     <NoWarn>$(NoWarn);TKSMPL0014;</NoWarn> 
 
     <!-- See https://github.com/CommunityToolkit/Windows/pull/567#issuecomment-2498739244 -->
-    <WarningsNotAsErrors>NU1901;NU1902;NU1903;NU1904</WarningsNotAsErrors>
+    <WarningsNotAsErrors>$(WarningsNotAsErrors);NU1901;NU1902;NU1903;NU1904</WarningsNotAsErrors>
     <NoWarn>$(NoWarn);TKSMPL0014;</NoWarn>
+
+    <!-- See https://github.com/CommunityToolkit/Windows/pull/609#issuecomment-2613505591 -->
+    <WarningsNotAsErrors>$(WarningsNotAsErrors);CS0419</WarningsNotAsErrors>
   </PropertyGroup>
 
   <Import Project="Windows.Toolkit.Common.props" />