Remove unused using statements

Author: johnsimons

src/ServiceControl.Persistence.Sql/NoOpCustomChecksDataStore.cs

@@ -4,7 +4,6 @@ namespace ServiceControl.Persistence.Sql;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using ServiceControl.Contracts.CustomChecks;
-using ServiceControl.CustomChecks;
 using ServiceControl.Persistence;
 using ServiceControl.Persistence.Infrastructure;
 

src/ServiceControl.Persistence.Sql/NoOpServiceControlSubscriptionStorage.cs

@@ -3,7 +3,6 @@ namespace ServiceControl.Persistence.Sql;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
-using NServiceBus;
 using NServiceBus.Extensibility;
 using NServiceBus.Unicast.Subscriptions;
 using NServiceBus.Unicast.Subscriptions.MessageDrivenSubscriptions;

src/ServiceControl.Persistence.Tests.Sql.SqlServer/PersistenceTestsContext.cs

@@ -1,8 +1,6 @@
 namespace ServiceControl.Persistence.Tests;
 
-using System;
 using System.Threading.Tasks;
-using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using ServiceControl.Persistence;