Try disabling running tests in parallel to fix DataProtectionProviderTests.System_UsesProvidedDirectoryAndCertificate failures

test/Microsoft.AspNetCore.DataProtection.Extensions.Test/Properties/AssemblyInfo.cs

@@ -0,0 +1,8 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Xunit;
+
+// Workaround for DataProtectionProviderTests.System_UsesProvidedDirectoryAndCertificate
+// https://github.com/aspnet/DataProtection/issues/160
+[assembly: CollectionBehavior(CollectionBehavior.CollectionPerAssembly)]