Implement GitHub Actions Workflow to Automatically Close Stale Issues

[mbkma]

This pull request introduces a new GitHub Actions workflow designed to automatically manage and close stale issues (issues where the last activity is older than 365 days) in our repository. This workflow will help us maintain a clean and manageable issue tracker by automatically marking issues as stale after a period of inactivity and subsequently closing them if no further activity occurs.

I plan to add this to every repo. Issues can still be labeled with a "do not stale" label, to prevent them from being automatically closed.

See https://docs.github.com/en/actions/managing-issues-and-pull-requests/closing-inactive-issues for a reference.

[lukefromdc]

What do others here think of this proposal? I have no problems with it myself, though I do not know of a way to test the actual code in question here short of a test issue followed by a year's delay to see what happens

[lukefromdc]

We have a new GEM problem in Travis deployment:

$ rvm use $(travis_internal_ruby) --fuzzy do ruby -S gem uninstall -aIx dpl

/home/travis/.rvm/gems/ruby-3.3.1/gems/cl-1.2.4/lib/cl/opts.rb:112:in `block in taint': undefined method `taint' for an instance of String (NoMethodError)

          [key, self[key] && self[key].secret? ? value.taint : value]

                                                      ^^^^^^

	from /home/travis/.rvm/gems/ruby-3.3.1/gems/cl-1.2.4/lib/cl/opts.rb:111:in `each'

	from /home/travis/.rvm/gems/ruby-3.3.1/gems/cl-1.2.4/lib/cl/opts.rb:111:in `map'

	from /home/travis/.rvm/gems/ruby-3.3.1/gems/cl-1.2.4/lib/cl/opts.rb:111:in `taint'

	from /home/travis/.rvm/gems/ruby-3.3.1/gems/cl-1.2.4/lib/cl/opts.rb:25:in `apply'

	from /home/travis/.rvm/gems/ruby-3.3.1/gems/cl-1.2.4/lib/cl/cmd.rb:62:in `initialize'

	from /home/travis/.rvm/gems/ruby-3.3.1/gems/dpl-2.0.3.beta.4/lib/dpl/provider.rb:196:in `initialize'

	from /home/travis/.rvm/gems/ruby-3.3.1/gems/cl-1.2.4/lib/cl/runner/default.rb:32:in `new'

	from /home/travis/.rvm/gems/ruby-3.3.1/gems/cl-1.2.4/lib/cl/runner/default.rb:32:in `cmd'

	from /home/travis/.rvm/gems/ruby-3.3.1/gems/cl-1.2.4/lib/cl/runner/default.rb:26:in `run'

	from /home/travis/.rvm/gems/ruby-3.3.1/gems/cl-1.2.4/lib/cl.rb:34:in `run'

	from /home/travis/.rvm/gems/ruby-3.3.1/gems/dpl-2.0.3.beta.4/lib/dpl/cli.rb:11:in `run'

	from /home/travis/.rvm/gems/ruby-3.3.1/gems/dpl-2.0.3.beta.4/bin/dpl:9:in `<top (required)>'

	from /home/travis/.rvm/gems/ruby-3.3.1/bin/dpl:25:in `load'

	from /home/travis/.rvm/gems/ruby-3.3.1/bin/dpl:25:in `<main>'