bpo-45711: Remove unnecessary normalization of exc_info by iritkatriel · Pull Request #29922 · python/cpython
exc_info should always be normalized, so it is not necessary to normalize it here.
It is also not necessary to copy the traceback to the exception instance. I added an assertion that the traceback does not change, and it broke only one test: test_exception_chaining_after_await_with_context_cycle
This is a test that raises the same exception twice, and makes sure that no context cycle is created. The test is not concerned with the traceback at all. We discussed the issue of the traceback change in this test in PR29780.