fixing test case for python 3.12

tests/test_broker.py

@@ -742,13 +742,14 @@ async def test_broker_broadcast_cancellation(broker):
     assert message
 
 
-def test_broker_socket_open_close(broker):
+@pytest.mark.asyncio
+async def test_broker_socket_open_close(broker):
 
     # check that https://github.com/Yakifo/amqtt/issues/86 is fixed
 
+    # mqtt 3.1 requires a connect packet, otherwise the socket connection is rejected
     static_connect_packet = b'\x10\x1b\x00\x04MQTT\x04\x02\x00<\x00\x0ftest-client-123'
-    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    s = socket.create_connection(("127.0.0.1", 1883))
-    server = ('localhost', 1883)
+    s.send(static_connect_packet)
-    sock.connect(server)
+    await asyncio.sleep(0.1)
-    sock.send(static_connect_packet)
+    s.close()
-    sock.close()