Fix upcoming type warning with swh.core > v0.1.2.
origin_visit_status_get_latest expects an int, not Optional[int]; but this error wasn't detected so far because mypy couldn't detect the type of the function.
The next release of swh.core fixes that issue, so this fix is now needed to not trigger a mypy error.
Migrated from D3637 (view on Phabricator)