Use compatible NuGet.Build.Tasks package

eng/tools/RepoTasks/RepoTasks.csproj

@@ -12,7 +12,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="NuGet.Build.Tasks" Version="5.3.0" />
+    <PackageReference Include="NuGet.Build.Tasks" Version="5.3.0-rtm.6192" />
     <PackageReference Include="Microsoft.Extensions.DependencyModel" Version="2.1.0" />
   </ItemGroup>