Fix labels missing from stale config

Author: JannisX11

.github/workflows/stale.yml

@@ -22,7 +22,14 @@ jobs:
             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.
-          close-issue-message: >
-              This issue has been automatically closed due to inactivity.
+          close-issue-message: false
           days-before-stale: 360
-          days-before-close: 28
+          days-before-close: 28
+          # Issues with these labels will never be considered stale
+          exempt-issue-labels:
+            - suggestion
+            - bug
+            - improvement
+            - upstream issue
+            - wontfix
+            - to investigate