移除 SysController 类中的 _hybridCaching 字段

删除了 SysController 类中的 _hybridCaching 字段。

src/Hotline.Api/Controllers/SysController.cs

@@ -45,7 +45,6 @@ namespace Hotline.Api.Controllers
     public class SysController : BaseController
     {
         private readonly IMapper _mapper;
-        private readonly IHybridCachingProvider _hybridCaching;
         private readonly IRepository<SystemSetting> _systemSettingsRepository;
         private readonly ISystemMenuRepository _systemMenuRepository;
         private readonly IRepository<SystemDicType> _sysDicTypeRepository;