Execute ConfigureServices without IWebHostBuilder

HostBuilderExtensions.cs

    public static class HostBuilderExtensions
    {
        public static IHostBuilder UseStartup<TStartup>(this IHostBuilder hostBuilder)
            where TStartup : class =>
            hostBuilder.ConfigureServices((ctx, sc) =>
            {
                var startupType = typeof(TStartup);
                var startupArgs = startupType
                    .GetConstructors().First()
                    .GetParameters()
                    .Select(p =>
                    {
                        if (typeof(IHostEnvironment).IsAssignableFrom(p.ParameterType))
                            return ctx.HostingEnvironment as object;
                        if (typeof(IConfiguration).IsAssignableFrom(p.ParameterType))
                            return ctx.Configuration as object;
                        return null;
                    }).ToArray();

                var startup = Activator.CreateInstance(typeof(TStartup), startupArgs);
                startupType
                    .GetMethod(nameof(IStartup.ConfigureServices), new[] {typeof(IServiceCollection)})
                    ?.Invoke(startup, new[] {sc});
            });
    }

Program.cs

using System;
using System.Linq;
using Hangfire;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace MultiContextWebApp
{
    public class Program
    {
        public static void Main(string[] args)
        {
            if (args.Contains("--worker"))
            {
                CreateConsoleHostBuilder(args).Build().Run();
                return;
            }

            CreateHostBuilder(args).Build().Run();
        }

        public static IHostBuilder CreateConsoleHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .UseStartup<Startup>()
                .ConfigureServices(collection => collection.AddHangfireServer())
                .UseConsoleLifetime();

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder => { webBuilder.UseStartup<Startup>(); });
    }
}