add a message when bot close a staled issue

Signed-off-by: Matthieu Gallien <matthieu_gallien@yahoo.fr>

.github/workflows/stale.yml

@@ -18,4 +18,6 @@ jobs:
                     stale-issue-message: 'This bug report did not receive an update in the last 4 weeks.
                                         Please take a look again and update the issue with new details,
                                         otherwise the issue will be automatically closed in 2 weeks. Thank you!'
+                    close-issue-message: "This bug report is getting automatically closed due to no answer
+                                          since the issue has been staled. Thank you!"
                     exempt-all-pr-milestones: true