Only mark unlabeled issues as stale.

.github/stale.yml

@@ -6,11 +6,7 @@ daysUntilStale: 14
 # Number of days of inactivity before a stale Issue or Pull Request is closed
 daysUntilClose: 7
 
-# Issues or Pull Requests with these labels will never be considered stale
-exemptLabels:
-  - "support"
-  - "bug"
-  - "security"
+onlyLabels: []
 
 # Label to use when marking as stale
 staleLabel: stale