add ignore stale label

Author: joshi-kamitsukasa

.github/workflows/close-inactive-issues.yml

@@ -18,6 +18,7 @@ jobs:
           stale-issue-message:
             'This issue is stale because it has been open for 30 days with no
             activity.'
+          exempt-issue-labels: 'not-stale'
           close-issue-message:
             'This issue was closed because it has been inactive for 14 days
             since being marked as stale.'