pyarrow module can't roundtrip tensor arrays

[wjones127]

Describe the bug

When exporting a tensor array (a kind of extension array) as a record batch, PyArrow segfaults. This does not happen if the batch is exported as a stream.

To Reproduce

The following test will fail in arrow-pyarrow-integration-testing/tests/test_sql.py:

def test_tensor_array():
    tensor_type = pa.fixed_shape_tensor(pa.float32(), [2, 3])
    inner = pa.array([float(x) for x in range(1, 7)] + [None] * 12, pa.float32())
    storage = pa.FixedSizeListArray.from_arrays(inner, 6)
    f32_array = pa.ExtensionArray.from_storage(tensor_type, storage)

    # Round-tripping as an array gives back storage type, because arrow-rs has
    # no notion of extension types.
    b = rust.round_trip_array(f32_array)
    assert b == f32_array.storage

    batch = pa.record_batch([f32_array], ["tensor"])
    b = rust.round_trip_record_batch(batch)
    assert b == batch

    del b

Expected behavior

We should round trip the array type successfully.

Additional context

The record batch exporting is done by exporting each individual array, but this separates the extension arrays from their metadata. I suspect PyArrow segfaults because it is receiving a plain array and then later told it is an extension in the final schema.