<PackageReference Include="System.Configuration.ConfigurationManager" Version="10.0.0-preview.7.25380.108" />

System.Configuration.NoSettingsVersionUpgradeAttribute

Specifies that a settings provider should disable any logic that gets invoked when an application upgrade is detected. This class cannot be inherited.
namespace System.Configuration { public sealed class NoSettingsVersionUpgradeAttribute : Attribute { public NoSettingsVersionUpgradeAttribute(); } }