Remove stale action

[jsstevenson]

As far as I can tell, the stale action has not, at least in recent years, actually closed an issue -- all closures have been manual (mostly by @korikuzma and @theferrit32). On the flip side, we've currently marked almost every open issue as stale-exempt. Is this action still a useful part of the workflow? Would it make sense to at least alter the configuration (maybe lengthen days-before-issue-stale) if not remove it entirely?

[korikuzma]

I'm pro removing it. I think that since we are constantly switching between projects, that this does not make sense for the current @ga4gh/vrs-python-maintainers .

[ahwagner]

Who am I to argue with our @ga4gh/vrs-python-maintainers? Remove it. 👍