public Mono<Long> countDeletedUsers(@Nullable DateRange dateRange) {
        return userRepository.countDeletedUsers(dateRange);
    }
@return Possible codes: {@link ResponseStatusCode#OK}
        {@link ResponseStatusCode#NOT_FRIEND_TO_QUERY_USER_PROFILE}
        {@link ResponseStatusCode#BLOCKED_USER_TO_QUERY_USER_PROFILE}
        {@link ResponseStatusCode#SERVER_INTERNAL_ERROR}
        {@link ResponseStatusCode#RESOURCE_NOT_FOUND}
turms-service/src/main/java/im/turms/service/domain/user/service/UserService.java