Review who can fork on collective organization?

Hi all,

I noticed that quite a few repositories in this `collective` organization are __forks__ from other organizations but, unlike `eea.facetednavigation` are totally random/unrelated to plone.

Looking at the [organization audit logs](https://github.com/organizations/collective/settings/audit-log) it mostly seems to be a UX problem on GitHub UI I would say 🍀

Should we revisit who can create forks on this organization? Maybe, just like one has to ask to get invited in this organization, the same could be done for forks? 🤔

There are left __+200__ forks in this organization, after deleting around +20 already.