Update stale.yml

Author: ethanshar

.github/stale.yml

@@ -13,6 +13,7 @@ onlyLabels: []
 # Issues or Pull Requests with these labels will never be considered stale. Set to `[]` to disable
 exemptLabels:
   - pinned
+  - WIP
   - bug
   - "feature request"
   - "typescript"
@@ -59,4 +60,4 @@ limitPerRun: 30
 
 # issues:
 #   exemptLabels:
-#     - confirmed
+#     - confirmed