Update Mac tests to run on Python 3.10

[rtibbles]

Summary

The Mac App is built against Python 3.10, but currently our Mac tests run on Python 3.6
Updates the Python version for Mac tests to Python 3.10 instead.

References

https://github.com/learningequality/kolibri-app/blob/main/.github/workflows/build_mac.yml#L55

Reviewer guidance

Do the Python tests still pass?

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Testing checklist

• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical user journeys are covered by Gherkin stories
• Critical and brittle code paths are covered by unit tests

PR process

• PR has the correct target branch and milestone
• PR has 'needs review' or 'work-in-progress' label
• If PR is ready for review, a reviewer has been added. (Don't use 'Assignees')
• If this is an important user-facing change, PR or related issue has a 'changelog' label
• If this includes an internal dependency change, a link to the diff is provided

Reviewer checklist

• Automated test coverage is satisfactory
• PR is fully functional
• PR has been tested for accessibility regressions
• External dependency files were updated if necessary (yarn and pip)
• Documentation is updated
• Contributor is in AUTHORS.md

[github-actions]

Build Artifacts

Asset type	Download link
PEX file	kolibri-0.16.1.dev0_git.20240227205856.pex
Windows Installer (EXE)	kolibri-0.16.1.dev0+git.20240227205856-unsigned.exe
Debian Package	kolibri_0.16.1.dev0+git.20240227205856-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.16.1.dev0+git.20240227205856-0.4.0.dmg
Android Package (APK)	kolibri-0.16.1.dev0+git.20240227205856-0.1.0-debug.apk
TAR file	kolibri-0.16.1.dev0+git.20240227205856.tar.gz
WHL file	kolibri-0.16.1.dev0+git.20240227205856-py2.py3-none-any.whl

[marcellamaki]

mac tests on 3.10 pass

[marcellamaki]

Since Python unit tests on Mac OS (3.6), merging without tests passing, as they will not run any more, with this update