Fix test_notoxini_help_still_works with tox v3.14.6

[stratakis]

Since tox version 3.14.6 test_notoxini_help_still_works
from test_z_cmdline.py fails due to tox-dev/tox#1539

Sync the tests from that tox version to fix the issue.

[gaborbernat]

tox-venv is being deprecated, so this issue no longer needs attention.

[stratakis]

While it's deprecated, it's still being used by projects e.g.: https://github.com/jaraco/jaraco.envs/blob/master/setup.cfg#L16

[gaborbernat]

Not everyone upgrades straigt away, however, eventually they should, virtualenv now does it out of the box what this project tries; and does it better.

[stratakis]

I agree with that, however while some upstreams might be slow to adopt some changes, the downstream flow will be even slower for it. My usecase is for Fedora, as for example, I cannot update the twine rpm to its latest version for its users, as it depends on jaraco.envs, which in turn depends on tox-venv.

From that perspective, tox-env is pretty much relevant (unless the associated stack gets updated to not require it, so an update to those packages downstream will fix it).

We can however include a downstream package on Fedora for that issue till the rest of the projects are caught up.

[gaborbernat]

I'll not be against this upgrading. But the maintainer of this package is no longer around (I can't do releases/merges). So IMHO will be easier to put in a PR to jaraco.envs to not use it, then trying to get this in. And in the end that probably leaves jaraco.envs also in a better place.