test_sharding_autosplit is flaky

[erikgrinaker]

https://neon-github-public-dev.s3.amazonaws.com/reports/main/12876223247/index.html#suites/6ed5c30d671bb24ca98ee7ff78b2e0c1/6beb44843b10e8f7/

/github/home/.cache/pypoetry/virtualenvs/non-package-mode-_pxWMzVK-py3.11/lib/python3.11/site-packages/allure_commons/_allure.py:221: in __call__
    return self._fixture_function(*args, **kwargs)
test_runner/fixtures/neon_fixtures.py:1541: in neon_env_builder
    with NeonEnvBuilder(
test_runner/fixtures/neon_fixtures.py:937: in __exit__
    self.env.storage_controller.assert_no_errors()
test_runner/fixtures/neon_fixtures.py:1711: in assert_no_errors
    assert_no_errors(
test_runner/fixtures/utils.py:527: in assert_no_errors
    assert not errors, f"First log error on {service}: {errors[0]}\nHint: use scripts/check_allowed_errors.sh to test any new allowed_error you add"
E   AssertionError: First log error on storage_controller: (2239, '2025-01-20T23:13:17.519038Z  WARN background_reconcile:auto_split{tenant_id=4fb01353bb8b6db9a25c3e5d95c2e868}: Error calling secondary download after shard split: pageserver API: NotFound: Shard 4fb01353bb8b6db9a25c3e5d95c2e868-0008 not found\n')
E   Hint: use scripts/check_allowed_errors.sh to test any new allowed_error you add