ci(stale-workflow): Change label names (#4272)

Author: thomaspoignant

.github/workflows/close-stale.yml

@@ -22,5 +22,5 @@ jobs:
           days-before-pr-stale: 45
           days-before-issue-close: 10
           days-before-pr-close: 10
-          exempt-issue-labels: p1,p2,p3,bug,dependencies,roadmap
+          exempt-issue-labels: "priority:P1,priority:P2,priority:P3,bug,dependencies,roadmap"
           exempt-assignees: thomaspoignant