Final `test_cancellation.py` group of the `run_in_actor` removal
(#477) — cancel-mechanics tests, so clean conversions,
- `test_cancel_via_SIGINT_other_task`: the 3 keep-alive
`run_in_actor(sleep_forever)` one-shots become plain
`start_actor()` daemons (an idle daemon needs no "main" task,
and no longer shares a single dup'd `namesucka` name).
- `spawn_sub_with_sync_blocking_task`: the middle layer's spawn
becomes a blocking `to_actor.run(spin_for, an=an)` which parks
awaiting the sync-sleeping grandchild's result until cancelled
from above.
- `test_cancel_while_childs_child_in_sync_sleep`: the
fire-and-forget middle-actor spawn becomes a bg
`to_actor.run()` task in a local task-nursery; the root's
`assert 0` cancels it, driving the same
graceful-cancel-then-zombie-reap cascade on the sync-blocked
grandchild. The `man_cancel_outer` xfail param is unchanged.
Zero live `run_in_actor()` call-sites remain in this suite.
Gate: full `test_cancellation.py` module green on both `trio`
(18p/1xf) + `mp_spawn` (18p/1xf).
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code