[QA] CI containers upgraded to tox 3.10.0

[Antoine Musso]

Hello,

I have upgraded tox to 3.10.0 for most of the CI Docker containers and 
CI jobs.  The previous version was 2.9.1.

The changelog for tox is:

* https://tox.readthedocs.io/en/latest/changelog.html


All containers/jobs have been updated except the special cases:

* operations-dnslint: uses the latest tox version available at the time 
of rebuild
* operations-puppet: pinned to 1.9.2 for historical reasons (but could 
probably be upgraded)


If a repository encounters an issue with the newer version of tox, it 
should probably be easy to fix. Else we can roll back the associated 
Jenkins job to the previous container.

The task was:
https://phabricator.wikimedia.org/T222512


-- 
Antoine "hashar" Musso