test_except_star can be simplified with sys.exception()

[iritkatriel]

migrating test_except_star to use sys.exception() instead of sys.exc_info() can make it a bit simpler. It won't cause any backporting issues because this test was only added in 3.11.

Linked PRs

• gh-102008: simplify test_except_star by using sys.exception() instead of sys.exc_info() #102009
• [3.11] gh-102008: simplify test_except_star by using sys.exception() instead of sys.exc_info() (GH-102009) #102116