Refresh SourceHut CI manifests

[bernardotorres]

Summary

• relax the Arch Python guardrail to accept Python 3.13 through 3.14
• move tests-minimal to debian/bookworm so the minimal dependency set still runs on Python 3.11
• keep tests-minimal focused on the minimal dependency matrix by dropping Docker-backed storage tests

Why

While validating #1211, a few unrelated CI issues surfaced:

• SourceHut no longer provides alpine/3.19
• the oldest supported aiohttp in the minimal dependency set still needs Python 3.11
• the Docker-backed DAV devkit containers fail with exit status 126 in tests-minimal, while storage coverage remains in archlinux-py313 and tests-pypi

[bernardotorres]

Feedback applied. Please take another look.

[WhyNotHugo]

Thanks!