Log Message:
misc/py-anita: update to 2.15.

Changes from 2.13:

Fix invalid escape sequences that cause warnings in Python 3.12.

In the deprecated anita.Release method, use https, and use
archive.netbsd.org for releases older than 9.0.

Ignoring a suffix of "-dvd" when deducing the architecture name from
the URL of an install ISO, to work around the issue of PR 58357.

Define a scratch disk for vax guests so that they can export ATF test
results to the host.

Support Xen pvshim.  From Manuel Bouyer.