`AttributeError` at the end of test run

[mkmkme]

Sometimes there's this traceback at the end of the CI run. This needs to be investigated.

  Traceback (most recent call last):
    File "/home/runner/work/valkey-py/valkey-py/valkey/cluster.py", line 1304, in __del__
      self.valkey_connection.close()
    File "/home/runner/work/valkey-py/valkey-py/valkey/client.py", line 536, in close
      self.connection_pool.disconnect()
    File "/home/runner/work/valkey-py/valkey-py/valkey/connection.py", line 1203, in disconnect
      connection.disconnect()
    File "/home/runner/work/valkey-py/valkey-py/valkey/connection.py", line 450, in disconnect
      conn_sock.shutdown(socket.SHUT_RDWR)
  AttributeError: 'bool' object has no attribute 'shutdown'