Add a github action for nudging or closing stale issues and PRs

[apetrynet]

Feature Request

As discussed in TSC meeting April 29th. Add a github action that helps keep issues and PRs moving forward or closing them.

Description

There is a github action called stale which is made for this. It has an extensive set of options available to tailor the behavior we'd like.

Context

Some issues or PRs go cold and are left unattended for a long time. Some due to getting resolved by similar issues or PRs, others get "lost in the pile" or suffer from prioritizing. Whatever the case, it would be nice to be reminded that these issues and PRs exist to move them forward or close them to decrease the backlog.

[jminor]

I just went through an manually added the stale label to a bunch of issues. I think this plugin could be useful with some specific configuration. Specifically, we could extend the timeouts to be much longer (e.g. 6 months, not 60 days) and we could use the exempt-issue-labels and related options to avoid closing stuff on the long term roadmap (e.g. the roadmap label).