[neutron][neutron-vpnaas] Reviews needed

Hi team,

We've got a few things that need to be looked at, so appreciate reviews from the Neutron team on this:

- Functional tests fixes for stable/yoga: https://review.opendev.org/c/openstack/neutron-vpnaas/+/840330 (and the rest of the chain) - TOX_CONSTRAINTS_FILE cleanup: https://review.opendev.org/c/openstack/neutron-vpnaas/+/822926 - README file cleanup: https://review.opendev.org/c/openstack/neutron-vpnaas/+/574679 - Backport of "ipsec rereadsecrets" for stable/wallaby: https://review.opendev.org/c/openstack/neutron-vpnaas/+/795884

I would appreciate if the Neutron core team can help move some of those patches since I'd like to get VPNaaS in a nice shape to make a release with those fixes :)

Thanks Mohammed