Workaround for dotnet/wpf#6792

Author: batzen

src/Directory.Build.Targets

@@ -18,4 +18,14 @@
         <Page Update="@(Page)" SubType="Designer" Generator="MSBuild:Compile" />
     </ItemGroup>
 
+    <Target Name="RemoveDuplicateAnalyzers" BeforeTargets="CoreCompile">
+      <!-- Work around https://github.com/dotnet/wpf/issues/6792 -->
+  
+      <ItemGroup>
+        <FilteredAnalyzer Include="@(Analyzer->Distinct())" />
+        <Analyzer Remove="@(Analyzer)" />
+        <Analyzer Include="@(FilteredAnalyzer)" />
+      </ItemGroup>
+    </Target>
+
 </Project>