Delete .github/workflows/stale-issue-pr.yaml

[bo0tzz]

Stale bots are very frustrating to users, and this project is not active enough for it to add anything meaningful to maintainers. Also see https://nostalebots.xyz/.

[cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}