clean MediatR useless references (#830)

Co-authored-by: cedri <cedri@BAS>

src/Web/Configuration/ConfigureWebServices.cs

@@ -1,8 +1,6 @@
 using MediatR;
 using Microsoft.eShopWeb.Web.Interfaces;
 using Microsoft.eShopWeb.Web.Services;
-using Microsoft.Extensions.Configuration;
-using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.eShopWeb.Web.Configuration;