`logging.shutdown()` should clear `logging._handlerList` if that's what it's called with

Bug report

Bug description:

In the wild, I've encountered situations where logging.shutdown gets called more than once in a process.

The current implementation is called with logging._handlerList by default, meaning that handlers can have their flush() and close() methods called more than once, which can cause bad things to happen if those handlers are not amenable to being closed more than once.

If logging.shutdown() is processing logging._handlerList, it should clear that list once it finished to prevent handlers having their flush() and close() methods called more than once.

CPython versions tested on:

3.12, CPython main branch

Operating systems tested on:

Linux, macOS

Linked PRs

• gh-129681

Bắt đầu từ điểm vào logging.shutdown() và kiểm tra cách nó xử lý logging._handlerList, bao gồm các lệnh gọi lặp lại đến flush() và close() được mô tả trong báo cáo. Xác nhận rằng shutdown xóa danh sách handler mặc định sau khi xử lý danh sách đó, đồng thời xác minh rằng các lệnh gọi shutdown lặp lại không xử lý lại cùng các handler.