Merge pull request #920 from dotnet/dependabot/nuget/Rx.NET/Source/Microsoft.NETCore.UniversalWindowsPlatform-6.2.8

Bump Microsoft.NETCore.UniversalWindowsPlatform from 6.1.9 to 6.2.8 in /Rx.NET/Source

Rx.NET/Source/tests/Tests.System.Reactive.Uwp.DeviceRunner/Tests.System.Reactive.Uwp.DeviceRunner.csproj

@@ -90,7 +90,7 @@
     <UseDotNetNativeToolchain>true</UseDotNetNativeToolchain>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform" Version="6.1.9" />
+    <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform" Version="6.2.8" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.runner.devices" Version="2.5.25" />
   </ItemGroup>