Fix upstream python2-virtualenv for OpenSUSE

[adferrand]

During #6794, we discovered that python2-virtualenv does not depend on python2-setuptools in OpenSUSE Leap 15+, while it usually do.

This is certainly a mistake, and this issue is here to inform about this to OpenSUSE maintainers.

[schoen]

@adferrand just coincidentally noticing the "area: SUSE" label and the possible Python 2/Python 3 difference here, is there any way that this issue could contribute to this problem (which at first glance is apparently a problem with an upstream library)?

#6808

[adferrand]

Hello @schoen, no I think the other issue is independant, and related to cryptography alone. The issue here is about a high level missing dependency for setuptools, so it impacts when creating the venv, by having basic pip/wheel/setuptools package missing.