Remove: [GitHub] old configuration file for stale-bot (#9998)

This bot was deactivated months (years?) ago.

.github/stale.yml

@@ -1,34 +0,0 @@
-daysUntilClose: 7
-staleLabel: stale
-closeComment: false
-exemptMilestones: true
-exemptAssignees: true
-
-issues:
-  daysUntilStale: 60
-  exemptLabels:
-  - pinned
-  - security
-  - "good first issue"
-  - regression
-  markComment: >
-    This issue has been automatically marked as stale because it has not had any activity in the last two months.
-
-    If you believe the issue is still relevant, please test on the latest nightly and report back.
-
-    It will be closed if no further activity occurs within 7 days.
-
-    Thank you for your contributions.
-
-pulls:
-  daysUntilStale: 30
-  exemptLabels:
-  - pinned
-  markComment: >
-    This pull request has been automatically marked as stale because it has not had any activity in the last month.
-
-    Please feel free to give a status update now, ping for review, or re-open when it's ready.
-
-    It will be closed if no further activity occurs within 7 days.
-
-    Thank you for your contributions.