Removes duplicate using using directives from Startup

Author: kevwhitt-hee

DigitalLearningSolutions.Web/Startup.cs

@@ -46,21 +46,13 @@ namespace DigitalLearningSolutions.Web
     using Microsoft.Extensions.Hosting;
     using Microsoft.FeatureManagement;
     using Microsoft.IdentityModel.Protocols.OpenIdConnect;
-    using Microsoft.IdentityModel.Tokens;
-    using Microsoft.AspNetCore.Http;
-    using System.Linq;
     using Microsoft.AspNetCore.Identity;
-    using AspNetCoreRateLimit;
     using static DigitalLearningSolutions.Data.DataServices.ICentreApplicationsDataService;
     using static DigitalLearningSolutions.Web.Services.ICentreApplicationsService;
     using static DigitalLearningSolutions.Web.Services.ICentreSelfAssessmentsService;
     using System;
     using IsolationLevel = System.Transactions.IsolationLevel;
-    using System.Collections.Concurrent;
     using Serilog;
-    using static DigitalLearningSolutions.Data.DataServices.ICentreApplicationsDataService;
-    using static DigitalLearningSolutions.Web.Services.ICentreApplicationsService;
-    using static DigitalLearningSolutions.Web.Services.ICentreSelfAssessmentsService;
 
     public class Startup
     {