tools: merge stalebot
(Ref: https://github.com/nodejs/admin/issues/860#issuecomment-2070045853
This PR makes the following changes to the stalebot:
- Merges the
issue
stalebot and thepr
stalebot into one - Reduce the time from 6 months to 2 months (and the stale->close time from 1 month to 2 weeks)
- Uses the latest version of stalebot (not @mhdawson's fork)
- Add more links to the message.
[!NOTE] This will affect open issues/PRs already, so we should go through those.