Appenders close and shutdown too early that make graceful shutdown logs missing

After we upgraded log4net to 2.0.10, we found all the log in IHostedService.StopAsync() are missing. Finally, we found it's because OnProcessExit called too early that before AspNetCore's WebHost gracefully shutdown: https://github.com/apache/logging-log4net/blob/2b8b17085995f64edb7c5892fb808c6e2af124ec/src/log4net/Core/LoggerManager.cs#L165