ci : add github action/stale to automatically flag and close inactive issues

[rohanKanojia]

What does this PR do?

This PR is part of DevTools Week.

• Adds a new workflow file:
  .github/workflows/stale.yml
• Uses actions/stale@v10
• Schedules daily runs at 02:00 UTC
• Automatically handles stale labeling, commenting, and closing issues and pull requests

It aims to replace the outdated repository https://github.com/che-incubator/chestnut-lite which is not working since January (see Chestnut actions page). Here a few benefits of using GitHub Actions instead of our own solution:

• Eliminates custom TypeScript code and maintenance overhead
• Fully supported by GitHub Actions
• Provides predictable, consistent stale management
• Easier to configure and update via YAML instead of code

Behavior

• Marks issues/PRs as stale after 180 days of inactivity
• Closes issues 7 days after being marked stale
• Stale issues/PRs are labeled lifecycle/stale
• Issues/PRs with the label lifecycle/frozen are exempt
• Comment messages guide users on how to mark the issue/PRs as active
• Automatically removes the stale label if activity resumes
• Limits operations to 100 issues per run (can be adjusted as per needs)

Screenshot/screencast of this PR

This workflow is supposed to run as a GitHub action every night and post comments on issues that are inactive since some time:

If even after marking issue/PR stale there is no activity. Issue is closed:

What issues does this PR fix or reference?

This issue is part of #23627

Replace https://github.com/che-incubator/chestnut-lite with actions/stale

How to test this PR?

I've tested it on a personal repo.

PR Checklist

As the author of this Pull Request I made sure that:

• The Eclipse Contributor Agreement is valid
• Code produced is complete
• Code builds without errors
• Tests are covering the bugfix or new feature
• The repository devfile is up to date and works
• Sections What issues does this PR fix or reference and How to test this PR completed
• Relevant user documentation updated
• Relevant contributing documentation updated
• CI/CD changes implemented, documented and communicated

Reviewers

Reviewers, please comment how you tested the PR when approving it.

[ibuziuk]

Any particular preference for this timing?

[rohanKanojia]

No, it was just an arbitrary value. We can change it to any value as per our needs.

[ibuziuk]

for what it worth, looks like https://github.com/che-incubator/chestnut-lite flow is working again, so not sure we need to merge the PR