`LoadJob.result()` ignores its default `retry`

[amatissart]

Environment details

• OS type and version: Fedora Linux 42
• Python version: 3.13.3
• pip version: 24.3.1
• google-cloud-bigquery version: 3.34.0

Steps to reproduce

Here is a failing unit test, to add in "test_job_retry.py".
The test fails with the DEFAULT_RETRY, and passes with a copy of the object.

@pytest.mark.parametrize(
 "result_retry",
 [
 pytest.param(
 {},
 id="default retry",
 ),
 pytest.param(
 {"retry": google.cloud.bigquery.retry.DEFAULT_RETRY.with_timeout(timeout=10.0)},
 id="custom retry object",
 ),
 ],
)
def test_retry_load_job_result(result_retry, PROJECT, DS_ID):
 from google.cloud.bigquery.dataset import DatasetReference
 from google.cloud.bigquery.job.load import LoadJob

 client = make_client()
 conn = client._connection = make_connection(
 dict(
 status=dict(state="RUNNING"),
 jobReference={"jobId": "id_1"}, 
 ),
 google.api_core.exceptions.ServiceUnavailable("retry me"),
 dict(
 status=dict(state="DONE"),
 jobReference={"jobId": "id_1"},
 statistics={"load": {"outputRows": 1}},
 ),
 )

 table_ref = DatasetReference(project=PROJECT, dataset_id=DS_ID).table("new_table")
 job = LoadJob("id_1", source_uris=None, destination=table_ref, client=client)
 result = job.result(**result_retry)

 assert job.state == "DONE"
 assert result.output_rows == 1

 # We made all the calls we expected to.
 assert conn.api_request.call_count == 3

The culprit appears to be this line:

python-bigquery/google/cloud/bigquery/job/base.py

Line 1000 in eb9c2af

kwargs = {} if retry is DEFAULT_RETRY else {"retry": retry}

introduced in #41
and whose expected behavior was broken after the refactoring of Retry in googleapis/python-api-core#462