Hangfire throws ObjectDisposedException during twice Dispose for BackgroundProcessingServer

[MiErnst]

The last comment in #2097 mentions that it should be fixed, but I'm still running into this issue when executing integration tests with a custom WebApplicationFactory. The service was simply registered using the WebApplicationBuilder (builder.Services.AddHangfireServer()).

I'm using version 1.8.17.

[Test Class Cleanup Failure (Foo.Tests.MyTest)]: System.ObjectDisposedException : Cannot access a disposed object.
Object name: 'Hangfire.Server.BackgroundProcessingServer'.
at Hangfire.Server.BackgroundProcessingServer.ThrowIfDisposed() in C:\projects\hangfire-525\src\Hangfire.Core\Server\BackgroundProcessingServer.cs:line 265
   at Hangfire.Server.BackgroundProcessingServer.SendStop() in C:\projects\hangfire-525\src\Hangfire.Core\Server\BackgroundProcessingServer.cs:line 128
   at Hangfire.BackgroundJobServer.SendStop() in C:\projects\hangfire-525\src\Hangfire.Core\BackgroundJobServer.cs:line 150
   at Hangfire.BackgroundJobServerHostedService.StopAsync(CancellationToken cancellationToken) in C:\projects\hangfire-525\src\Hangfire.NetCore\BackgroundJobServerHostedService.cs:line 128
   at Microsoft.Extensions.Hosting.Internal.Host.ForeachService[T](IEnumerable`1 services, CancellationToken token, Boolean concurrent, Boolean abortOnFirstException, List`1 exceptions, Func`3 operation)
   at Microsoft.Extensions.Hosting.Internal.Host.StopAsync(CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactory`1.DisposeAsync()
   at Foo.Tests.IntegrationTests.Tests.Base.TestApplicationFactory`1.DisposeAsync() in /azp/_work/1/s/tests/Foo.Tests/IntegrationTests/Tests/Base/TestApplicationFactory.cs:line 29
   at Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactory`1.Dispose(Boolean disposing)
   at Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactory`1.Dispose()