Python 3.12 unit tests fail with `tuple index out of range`

[parthea]

See build log here from PR #455

.nox/unit-3-12/lib/python3.12/site-packages/_pytest/assertion/rewrite.py:186: in exec_module
    exec(co, module.__dict__)
tests/unit/pubsublite/cloudpubsub/internal/subscriber_impl_test.py:32: in <module>
    from google.cloud.pubsublite.cloudpubsub.internal.subscriber_impl import SubscriberImpl
google/cloud/pubsublite/cloudpubsub/internal/subscriber_impl.py:33: in <module>
    from google.cloud.pubsublite.cloudpubsub.subscriber_client_interface import (
google/cloud/pubsublite/cloudpubsub/__init__.py:18: in <module>
    from .publisher_client import AsyncPublisherClient, PublisherClient
google/cloud/pubsublite/cloudpubsub/publisher_client.py:23: in <module>
    from google.cloud.pubsublite.cloudpubsub.internal.make_publisher import (
google/cloud/pubsublite/cloudpubsub/internal/make_publisher.py:32: in <module>
    from google.cloud.pubsublite.internal.wire.make_publisher import (
google/cloud/pubsublite/internal/wire/make_publisher.py:40: in <module>
    from google.cloud.pubsublite.internal.wire.single_partition_publisher import (
google/cloud/pubsublite/internal/wire/single_partition_publisher.py:65: in <module>
    class SinglePartitionPublisher(
google/cloud/pubsublite/internal/wire/single_partition_publisher.py:201: in SinglePartitionPublisher
    @overrides
.nox/unit-3-12/lib/python3.12/site-packages/overrides/overrides.py:88: in overrides
    return _overrides(method, check_signature, check_at_runtime)
.nox/unit-3-12/lib/python3.12/site-packages/overrides/overrides.py:104: in _overrides
    for super_class in _get_base_classes(sys._getframe(3), global_vars):
.nox/unit-3-12/lib/python3.12/site-packages/overrides/overrides.py:142: in _get_base_classes
    for class_name_components in _get_base_class_names(frame)
.nox/unit-3-12/lib/python3.12/site-packages/overrides/overrides.py:183: in _get_base_class_names
    extends.append(("attr", co.co_names[oparg]))
E   IndexError: tuple index out of range