Consider removing the reuse_existing_virtualenvs parameter from noxfile.py

[flpm]

Currently nox is configured to reuse virtualenvs. This caused some issues with translations when some of the Sphinx modules were not updated.

Based on the informal discussion in Slack, multiple people voiced the preference to remove it (I lean towards that as well). We can use this issue to gather more feedback and make a decision.

python-package-guide/noxfile.py

Line 6 in cdbdf85

nox.options.reuse_existing_virtualenvs = True

See issue #390 for how this parameter caused trouble while building the Spanish translation.

[willingc]

Seems reasonable to change. Do you wish to open a PR?

[flpm]

👍 I will make a PR