Update stale.yml

Author: ezeholz

.github/workflows/stale.yml

@@ -24,7 +24,7 @@ jobs:
           days-before-issue-close: 7
           days-before-pr-close: 7
           stale-issue-label: 'stale'
-          exempt-issue-labels: 'working,help wanted'
+          exempt-issue-labels: 'working,help wanted,PR Welcome!'
           stale-pr-label: 'stale'
           exempt-pr-labels: 'working,help wanted'
           exempt-all-milestones: true