style: ruff format tests/test_backends.py (PR #1322)

tests/test_backends.py

@@ -730,9 +730,9 @@ def test_make_client_quarantines_only_on_first_call_per_palace(tmp_path, monkeyp
     ChromaBackend.make_client(palace_path)
     ChromaBackend.make_client(palace_path)
 
-    assert calls == [palace_path], (
-        "quarantine_stale_hnsw should fire once per palace per process, not on every reconnect"
-    )
+    assert calls == [
+        palace_path
+    ], "quarantine_stale_hnsw should fire once per palace per process, not on every reconnect"
 
 
 def test_make_client_quarantines_each_palace_independently(tmp_path, monkeypatch):
@@ -820,9 +820,9 @@ def test_client_quarantines_only_on_first_call_per_palace(tmp_path, monkeypatch)
     finally:
         backend.close()
 
-    assert calls == [palace_path], (
-        "quarantine_stale_hnsw should fire once per palace per process from _client(), not on every call"
-    )
+    assert (
+        calls == [palace_path]
+    ), "quarantine_stale_hnsw should fire once per palace per process from _client(), not on every call"
 
 
 # ── _pin_hnsw_threads (per-process retrofit, separate from this PR's gate) ──