tests: ruff fixes

scripts/ytdlp_test.py

@@ -14,7 +14,7 @@ def brozzle_page(worker, page) -> bool:
 
     # This gets assigned after a video is captured; if an
     # exception was raised by yt-dlp, it never gets assigned.
-    if not "videos" in page:
+    if "videos" not in page:
         return False
 
     if len(page.videos) > 0:

tests/test_frontier.py

@@ -944,7 +944,6 @@ def test_max_claimed_sites(rethinker):
         ],
         "max_claimed_sites": 3,
     }
-    seeds_seen = []
     job = brozzler.new_job(frontier, job_conf)
 
     assert job.id