ci: Add ability to exempt items from stale workflow (github-aws-runners#2211)

Author: ScottGuymer

.github/workflows/stale.yml

@@ -25,3 +25,4 @@ jobs:
           days-before-stale: 30
           days-before-close: 10
           close-issue-label: "abandoned"
+          exempt-issue-labels: "stale:exempt"