Update dependencies from https://dev.azure.com/dnceng/internal/_git/dotnet-wpf-int build 20210530.2 (#4602)

[main] Update dependencies from dnceng/internal/dotnet-wpf-int

Author: dotnet-maestro[bot]

eng/Version.Details.xml

@@ -61,9 +61,9 @@
       <Uri>https://github.com/dotnet/runtime</Uri>
       <Sha>f54a4cd54f73731ac6117fe8c98e24c1792401b4</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.Wpf.DncEng" Version="6.0.0-preview.6.21278.2">
+    <Dependency Name="Microsoft.DotNet.Wpf.DncEng" Version="6.0.0-preview.6.21280.2">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-wpf-int</Uri>
-      <Sha>1489cb7f8770ad66aef462957016806862709f4b</Sha>
+      <Sha>7eda04aa4c0b28146b8036ebdf54e5997aa9aeb4</Sha>
     </Dependency>
     <Dependency Name="System.IO.Packaging" Version="6.0.0-preview.6.21278.2" CoherentParentDependency="Microsoft.Private.Winforms">
       <Uri>https://github.com/dotnet/runtime</Uri>

eng/Versions.props

@@ -84,6 +84,6 @@
     <SystemReflectionMetadataLoadContextPackage>System.Reflection.MetadataLoadContext</SystemReflectionMetadataLoadContextPackage>
   </PropertyGroup>
   <PropertyGroup>
-    <MicrosoftDotNetWpfDncEngVersion>6.0.0-preview.6.21278.2</MicrosoftDotNetWpfDncEngVersion>
+    <MicrosoftDotNetWpfDncEngVersion>6.0.0-preview.6.21280.2</MicrosoftDotNetWpfDncEngVersion>
   </PropertyGroup>
 </Project>