[C++][FlightRPC] Memory alignment related warning

### Describe the usage question you have. Please include as many useful details as possible.

It seems the RecordBatch returned from doGet in Flight RPC is not memory aligned.

I tested the simple program below:
``` python
import duckdb
import pyarrow as pa
import pyarrow.flight as flight

# connect to an in-memory database
con = duckdb.connect()

client = pa.flight.connect(('localhost', 8815))

reader = client.do_get(flight.Ticket(b'ints')).to_reader()

results = con.execute("SELECT * FROM reader").arrow()

print(results)
```
The code finishes, tut the following warning:
```
C:/arrow/cpp/src/arrow/acero/source_node.cc:76: An input buffer was poorly aligned. This could lead to crashes or poor performance on some hardware. Please ensure that all Acero sources generate aligned buffers, or change the unaligned buffer handling configuration to silence this warning.
```
I'm wondering is there any option I can turn on to make the record batch returned by flight rpc aligned?

Thanks.

### Component(s)

C++, FlightRPC