Enhancement: Don't add users for repos over x contributors?

Example -- some large repos encourage many people to make a small commit. If there are 10,000 users of a repo like that, do we really want to be adding them all to PortfoliOSS and tracking them even if they don't belong to an org? Probably not.

I want to ensure the next run of PortfoliOSS doesn't have 160,000 users to restore.

Start by tracing the next PortfoliOSS run and the user-restoration path described in the issue. Define how a repository contributor threshold should be selected and applied; done means large repositories do not add every unaffiliated contributor and the restored user count remains bounded.

Written by the indexing model from the issue text.