arrow

GH-37993: [CI] Fix conda-integration build (#37990)

### Rationale for this change

The conda-integration build has recently started failing:
https://github.com/apache/arrow/actions/runs/6393852866/job/17353952453

Apparently this is because conda-forge is now providing Python 3.12 by default, and pythonnet [does not support it yet](https://github.com/pythonnet/pythonnet/pull/2249).

### What changes are included in this PR?

Avoid using Python 3.12 for Archery in conda-integration build.

### Are these changes tested?

Yes, by construction.

### Are there any user-facing changes?

No.
* Closes: #37993

Authored-by: Antoine Pitrou <antoine@python.org>
Signed-off-by: Raúl Cumplido <raulcumplido@gmail.com>