arrow

GH-25118: [Python] Make NumPy an optional runtime dependency   (#41904)

### Rationale for this change

Being able to run pyarrow without requiring numpy.

### What changes are included in this PR?

If numpy is not present we are able to import pyarrow and run functionality.
A new CI job has been created to run some basic tests without numpy.

### Are these changes tested?

Yes via CI.

### Are there any user-facing changes?

Yes, NumPy can be removed from the user installation and pyarrow functionality still works

* GitHub Issue: #25118

Lead-authored-by: Raúl Cumplido <raulcumplido@gmail.com>
Co-authored-by: Joris Van den Bossche <jorisvandenbossche@gmail.com>
Co-authored-by: Antoine Pitrou <pitrou@free.fr>
Signed-off-by: Antoine Pitrou <antoine@python.org>