Support Python 3.14

[azure-cli-python-upgrade-bot]

This issue tracks the Python 3.13 → 3.14 rollout for
Azure CLI, following the precedent of
#32869 (3.14) and
#29640 (3.13).

The azure-cli-bump item below is opened automatically by the
python-upgrade bot. The other items are accumulators — append PR / issue links
as sub-bullets (or in comments below) as work lands, and tick the box once
that workstream is complete.

Plan

• prereq-knack — knack supports Python 3.14
• prereq-aaz-dev — aaz-dev supports Python 3.14
• prereq-azdev — azdev supports Python 3.14
• ci-passes — CI passes with Python 3.14 (dependency bumps and azure-cli-extensions pipeline included)
• extensions-compatible — Published extensions compatible with Python 3.14
• azure-cli-bump — Support Python 3.14 (bump embedded interpreter: 3.13.13 → 3.14.5)

[YangAn-microsoft]

Closing duplicate. Tracked in #12.