Method resize

include/rabitqlib/utils/buffer.hpp:79–84

    [[nodiscard]] auto has_next() const -> bool { return cur_ < size_; }

    void resize(size_t new_size) {
        this->capacity_ = new_size;
        data_ = std::vector<AnnCandidate<T>, memory::AlignedAllocator<AnnCandidate<T>>>(
            capacity_ + 1
        );
    }

    void copy_results(PID* knn) const {
        for (size_t i = 0; i < size_; ++i) {