Marking plugins for adoption

[Adrien Lecharpentier]

Hello,

while I was updating some permissions I had on plugins deployment to Artifactory, I noticed that a lot of plugins have no developers listed. 

This means that no one is maintaining them.

So I proposed https://github.com/jenkins-infra/repository-permissions-updater/pull/2891 to automatically mark plugins with no developers as up for adoption. 

Currently, 104 plugins are mark as such, and only 92 are labelled with way in the update center. However, I detect at least 327 plugins with no developers. Probably more but some permission files have no `github` info.

It could be seen as harsh but I think it is just fair to users and us. 

What do you think? 

-- Adrien

[Damien Duportal]

That looks a sane change. Worst case, any developer could still claim back their maintainership if someone adopt their plugin.

Thanks for this work Adrien!