fix: ruff-format test_parallel_processor.py after merge (#873)

The rebase/merge of the worker-health + check_worker_health test additions
joined two test sections without a ruff pass, leaving a blank-line spacing the
CI formatter rejects. Apply ruff format.

Co-authored-by: n24q02m <n24q02m@outlook.com>

Author: n24q02m

tests/test_parallel_processor.py

@@ -664,6 +664,8 @@ def test_semi_ordered_map_empty():
     assert result == []
     # Verify processes are joined and list is cleared
     assert len(pool.processes) == 0
+
+
 def test_semi_ordered_map_interrupted_no_hang():
     """Test that semi_ordered_map does not hang when consumption is interrupted early."""
     pool = ParallelWorkerPool(worker=SlowWorker, config=PoolConfig(num_workers=1))
@@ -699,6 +701,8 @@ def test_semi_ordered_map_start_failure():
     # queues should be None or handled safely
     assert pool.input_queue is None
     assert pool.output_queue is None
+
+
 def test_check_worker_health_healthy():
     """Test check_worker_health does not raise when all processes are alive or exited cleanly."""
     pool = ParallelWorkerPool(worker=SquareWorker, config=PoolConfig(num_workers=2))