DOC: to_pylist returns a pandas.Timestamp instead of datetime.datetime when the type is timestamp[ns]

### Describe the enhancement requested

```
In [2]: import pyarrow as pa; from datetime import datetime

In [4]: pa.array([datetime(2023, 1, 1)], type=pa.timestamp("ns")).to_pylist()
Out[4]: [Timestamp('2023-01-01 00:00:00')]
```

From the docs, I assumed `Convert to a list of native Python objects.` means I should always expected a `datetime.datetime`object, but since I suppose it cannot handle nanosecond components this method returns a `pandas.Timestamp` when the unit is `"ns"`

### Component(s)

Python

Start by reproducing the pa.array(..., type=pa.timestamp("ns")).to_pylist() example from the issue and inspect the Python conversion path for timestamp[ns] values. Check the documentation wording for to_pylist and existing tests around timestamp conversion; done means the returned type and its documentation agree for nanosecond timestamps.

Written by the indexing model from the issue text.