Restore asyncio marker on the reset-to-seq test

Inserting the heartbeat test above it took over its decorator, leaving
the reset test without one. Harmless under asyncio_mode = auto, but it
put an unrelated test in the diff.

Author: caspervonb

nats-jetstream/tests/test_consumer.py

@@ -1112,6 +1112,7 @@ async def _silent() -> None:
         await asyncio.wait_for(pending, timeout=10)
 
 
+@pytest.mark.asyncio
 async def test_consumer_reset_to_seq(jetstream: JetStream):
     """Reset a consumer forward to a specific stream sequence (ADR-60).