save_bulk: Ensure high priority scheduling for first visits of origins

Related to swh/devel/swh-scheduler#4687.

swh/lister/save_bulk/lister.py

@@ -289,6 +289,7 @@ class SaveBulkLister(Lister[SaveBulkListerState, SaveBulkListerPage]):
             max_origins_per_page=max_origins_per_page,
             max_pages=max_pages,
             enable_origins=enable_origins,
+            first_visits_queue_prefix="save_bulk",
         )
         self.rejected_origins: Set[RejectedOrigin] = set()
         self.per_page = per_page

swh/lister/save_bulk/tests/test_lister.py

@@ -97,6 +97,9 @@ def test_bulk_lister_valid_origins(swh_scheduler, requests_mock, mocker):
         scheduler=swh_scheduler,
         per_page=PER_PAGE,
     )
+
+    assert lister_bulk.first_visits_queue_prefix == "save_bulk"
+
     stats = lister_bulk.run()
 
     expected_nb_origins = len(SUBMITTED_ORIGINS)