Upgrade morango, cryptography and dependency versions.

[rtibbles]

Summary

• Upgrades morango to version that is tested against newer version of cryptography library and that drops support for Python 3.4 and 3.5
• Upgrades cryptography and its dependencies to the latest version supported by Python 2.7
• Updates C extension bundling to ensure that we properly bundle for all supported Python 3 versions
• Updates C extension bundling to ensure that we bundle for Python 3.8 on Windows
• Updates tox tests to run on Python 3.8 on Windows

Reviewer guidance

Hopefully ameliorates #9908

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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-0.16.0b9.dev0_git.86.ge75258a6.pex
Windows Installer (EXE)	kolibri-0.16.0b9.dev0+git.86.ge75258a6-unsigned.exe
Debian Package	kolibri_0.16.0b9.dev0+git.86.ge75258a6-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.16.0b9.dev0+git.86.ge75258a6-0.3.0.dmg
Android Package (APK)	kolibri-0.16.0b9.dev0+git.86.ge75258a6-0.1.0-debug.apk
TAR file	kolibri-0.16.0b9.dev0+git.86.ge75258a6.tar.gz
WHL file	kolibri-0.16.0b9.dev0+git.86.ge75258a6-py2.py3-none-any.whl

[rtibbles]

Looks like I'm going to have to do some tweaks to properly handle C extension installation now. Will do some more work on this.

[rtibbles]

Our C extension downloading code appears to be unfamiliar with some of the new fangled wheel file names on PyPi these days, so is breaking.

[rtibbles]

Have confirmed that this allows Windows to be properly tested on Python 3.8, which is very positive! Reverting that change, and now attempting to fix the build issue. If I can get that working, we can release a new v0.7.x version of morango to make this mergerable.

[bjester]

Ran the morango integration tests 👍

[pcenov]

Tested on Windows 7, 10 and 11 without noticing new issues with the installer or change in the CPU usage which is fluctuating and is the same as reported in #11622.