Bug#1035635: tox: Upgrading to tox 4

[Stefano Rivera <stefanor@debian.org>]

Hi Release Team!

For the tox 4 transition, I have changes in dh-python staged (and in
experimental) but the autopkgtests require tox 4, so I can't upload them
until we're ready to pull the trigger on the transition.

All the fallout I could find is documented in blocking bugs of this bug
and the dh-python bug (1035675).

Some of the fixes were staged in experimental, because we were in freeze
at the time.

Some of the packages need upstream work, and would have to be removed
from testing for the transition.

Please let me know when we should go ahead with this.

Stefano

-- 
Stefano Rivera
  http://tumbleweed.org.za/
  +1 415 683 3272