[CD-1222] Remediate casedev-python package vulnerabilities

[andrazk]

Summary

Remediates GitHub Dependabot medium findings for CaseMark/casedev-python by updating the Python dependency lock to patched versions:

• aiohttp -> 3.14.1
• idna -> 3.18
• pytest -> 9.1.0

To remove vulnerable Python 3.9-only lock resolutions, this also raises the package support floor from Python 3.9 to Python 3.10 and updates the local pin, docs, pyright config, and staging validation matrix accordingly.

Vanta

https://app.vanta.com/c/casemark/tests/packages-checked-for-vulnerabilities-v2-records-closed-github-dependabot-medium

Validation

• uv lock --check
• Targeted uv.lock version check for aiohttp, idna, and pytest
• uv build passed

Notes

uv run pytest -q was attempted but stopped after broad early failures; it was not useful signal for this dependency-only remediation and should be reviewed separately from the lockfile update.