Upgrade Microsoft.NET.Test.Sdk to 15.6.1 (#1627)
Upgrade Microsoft.NET.Test.Sdk to 15.6.1 (#1627)


aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore