Clean up unused imports

PluralKit.API/Startup.cs

@@ -1,20 +1,8 @@
-using System;
-using System.Collections.Generic;
-using System.Data;
-using System.Linq;
-using System.Threading.Tasks;
-using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
-using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.HttpsPolicy;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.Options;
-using NodaTime;
-using NodaTime.Serialization.JsonNet;
-using Npgsql;
 
 namespace PluralKit.API
 {