py-anyio: updated to 4.1.0

4.1.0

- Adapted to API changes made in Trio v0.23:

  - Call ``trio.to_thread.run_sync()`` using the ``abandon_on_cancel`` keyword argument
    instead of ``cancellable``
  - Removed a checkpoint when exiting a task group
  - Renamed the ``cancellable`` argument in ``anyio.to_thread.run_sync()`` to
    ``abandon_on_cancel`` (and deprecated the old parameter name)
  - Bumped minimum version of Trio to v0.23
- Added support for voluntary thread cancellation via
  ``anyio.from_thread.check_cancelled()``
- Bumped minimum version of trio to v0.23
- Exposed the ``ResourceGuard`` class in the public API
- Fixed ``RuntimeError: Runner is closed`` when running higher-scoped async generator
  fixtures in some cases
- Fixed discrepancy between ``asyncio`` and ``trio`` where reraising a cancellation
  exception in an ``except*`` block would incorrectly bubble out of its cancel scope

(adam)