Method add_task

imperative/python/src/helper.h:96–102

public:
    template <typename T>
    void add_task(T&& task) {
        // CPython never dlclose an extension so
        // finalized means the interpreter has been shutdown
        if (!finalized) {
            queue.add_task(std::forward<T>(task));
        }
    }
    void wait_all_task_finish() { queue.wait_all_task_finish(); }
    ~PyTaskDipatcher() {
        finalized = true;