[Python] Flight objects like FlightEndpoint cannot be pickled

### Describe the bug, including details regarding any error messages, version, and platform.

e.g.

```
>>> pyarrow.__version__
'11.0.0'
>>> ep = pyarrow.flight.FlightEndpoint(ticket=pyarrow.flight.Ticket(b"foo"), locations=["grpc://localhost:3000"])
>>> ep
locations: []>
>>> pickle.dumps(ep)
Traceback (most recent call last):
File "", line 1, in
File "stringsource", line 2, in pyarrow._flight.FlightEndpoint.__reduce_cython__
TypeError: self.endpoint cannot be converted to a Python object for pickling
```

### Component(s)

Python

Reproduce the example with pyarrow 11.0.0 using pyarrow.flight.FlightEndpoint and pickle.dumps. Start from the Python Flight binding shown in the pyarrow._flight traceback; done means FlightEndpoint can be serialized without the reported TypeError and can be unpickled successfully.

Written by the indexing model from the issue text.