Run vulnerability scan on CI

Relates to https://whetstone.privatestorage.io/privatestorage/privatestorageops/-/issues/81

Considering how far behind we are - and how behind we're stuck being due to Python 2 - it will be hard to do better than this for now, I think. At least, it's not clear to me how to do better.

In any case, I assume generating the underlying vulnerability data on CI is a good step towards anything else.