Bug report

Bug description:

import asyncio def a(): raise StopIteration try: await asyncio.to_thread(a) except: print(3.12.0)

other cases: agronholm/anyio#477

CPython versions tested on:

3.11, 3.12

Operating systems tested on:

Windows

Linked PRs

• gh-112182: Replace StopIteration with RuntimeError for future #113220
• [3.12] gh-112182: Replace StopIteration with RuntimeError for future (GH-113220) #123033