fix(user_management): remove redundant role filter check

- Remove unnecessary condition for DashboardUserRole.none
- Directly assign dashboardRole to filter when it's not null

Author: fulleni

lib/user_management/bloc/user_management_bloc.dart

@@ -130,11 +130,7 @@ class UserManagementBloc
     }
 
     if (state.dashboardRole != null) {
-      // When 'Any' is selected, dashboardRole is null, so we don't add the filter.
-      // Otherwise, we filter by the specific role name.
-      if (state.dashboardRole != DashboardUserRole.none) {
-        filter['dashboardRole'] = state.dashboardRole!.name;
-      }
+      filter['dashboardRole'] = state.dashboardRole!.name;
     }
 
     return filter;