Re-add stalebot-esque github Action

[uberbrady]

This is a first stab at re-adding Github's "Stale Action" task to the repo.

I have it running just in "Dry run" mode for now, until we can tweak it.

I'm still a little nervous about some of the Emojis in the configuration, one of the online YAML parsers I found didn't seem to like it.

I figure we can tweak it around a little bit until we get it to where we want it, then let it rip. I think for the initial run, since we have around 1.6k open issues, it might make sense to have it run hourly, with a higher number of operations-per-run, until we burn through the backlog - then we can tone it down and let it just run at the default frequency of once per day. But we can see how it works and then adjust, I suppose.

[what-the-diff]

PR Summary

• Removed Stale Configurations
  The removal of .github/stale.yml indicates we have cleaned out old, unused configurations.

• Added New Workflow Configurations
  We introduced .github/workflows/stale.yml, implying that we have set up new processes for handling stale (inactive or outdated) issues in the project.