Cleanup stale pull requests when not activity during defined time period

[maZahaca]

Add a section to the config:

stale_pull_cleanup:
  enabled: true
  duration: 7d

Check any activity in PR:

• PR review comment
• PR commit

If non of these happened during stale_pull_cleanup.duration, trigger delete deployment for PR.

Any new commit or /deploy comment will make a deployment again.

[maZahaca]

fixed in https://github.com/InfraWay/gh-deploy-bot/releases/tag/v0.4.0