Need to keep traceback alive in WITH_EXCEPT_START

Bug report

Bug description:

Currently in WITH_EXCEPT_START the interpreter loop gets the traceback from the exception object and then immediately decref's it before calling the __exit__ function. But the __exit__ function may not incref the traceback (if it's not an interpretedPython function) and could cause the traceback to be replaced on the exception, leading it holding onto a freed traceback.

CPython versions tested on:

CPython main branch, 3.12

Operating systems tested on:

Linux

Linked PRs

• gh-130562
• gh-130626

先查看关联的 PR gh-130562 和 gh-130626，然后定位 CPython 中解释器循环的 WITH_EXCEPT_START 实现。验证在 exit 运行期间 traceback 仍然有效，并为报告的替换和生命周期场景添加或更新覆盖测试。