added issue-closer workflow.

[BjornFJohansson]

This workflow is supposed to close old and stale issues.
This may or not be something we want.
My motivation was to clean up the issues so that they are more manageable.
This may or not be the best way to do this.

What do you think?

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

@@           Coverage Diff           @@
##           master     #670   +/-   ##
=======================================
  Coverage   95.10%   95.10%           
=======================================
  Files          39       39           
  Lines        6393     6393           
  Branches      945      945           
=======================================
  Hits         6080     6080           
  Misses        246      246           
  Partials       67       67           

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[manulera]

I think this makes more sense for projects where the issues would be created by community members, to keep only what the maintainers care about or what's been talked about. In our case, I think the issues are not so many and tend to be edge-casey or pending things that we came across and documented for the future.

[BjornFJohansson]

Closing for now