test_timeline_ancestor_detach_idempotent_success: increase timeout

[erikgrinaker]

Consider increasing the timeout here, unless there are signs of actual problems.

See https://neonprod.grafana.net/d/fddp4rvg7k2dcf/regression-test-failures?orgId=1&var-test_name=test_timeline_ancestor_detach_idempotent_success%5Bshards_initial_after2%5D&from=now-7d&to=now&timezone=utc&var-restrict=true&var-max_count=100&var-reference=$__all&var-ignore_reference=refs%2Fpull%2F0000%2Fmerge

test_runner/regress/test_timeline_detach_ancestor.py:639: in test_timeline_ancestor_detach_idempotent_success
    env.storage_controller.reconcile_until_idle()
test_runner/fixtures/neon_fixtures.py:2091: in reconcile_until_idle
    raise RuntimeError("Timeout in reconcile_until_idle")
E   RuntimeError: Timeout in reconcile_until_idle

[arpad-m]

Hmm yeah looking at the storcon logs of this run, filtering for "Applying optimization", it seems to migrate the shards one by one from one location to the other, so there is a constant progress, and not a hang. Same goes for two other flaky failures I looked at.

So increasing the timeout makes the most sense I think.