Remove deprecated Stale Bot config

The stale app is deprecated and this repository is no longer maintained.
See: https://github.com/apps/stale

.github/stale.yml

@@ -1,35 +0,0 @@
-# Number of days of inactivity before an issue becomes stale
-daysUntilStale: 90
-# Number of days of inactivity before a stale issue is closed
-daysUntilClose: 7
-# Issues with these labels will never be considered stale
-exemptLabels:
-    - a:bug
-    - re:security
-    - re:privacy
-    - re:Tor
-    - in:dao
-    - $BSQ bounty
-    - good first issue
-    - Epic
-    - a:feature
-    - is:priority
-# Label to use when marking an issue as stale
-staleLabel: was:dropped
-# Comment to post when marking an issue as stale. Set to `false` to disable
-markComment: >
-    This issue has been automatically marked as stale because it has not had
-    recent activity. It will be closed if no further activity occurs. Thank you
-    for your contributions.
-# Comment to post when closing a stale issue. Set to `false` to disable
-closeComment: >
-    This issue has been automatically closed because of inactivity.
-    Feel free to reopen it if you think it is still relevant.
-
-pulls:
-    daysUntilStale: 30
-    markComment: >
-        This pull request has been automatically marked as stale because it has not had
-        recent activity. It will be closed if no further activity occurs. Thank you
-        for your contributions.
-