ci: update stale action (#4931)

to suppress node.js 12 deprecation warning in actions

Signed-off-by: Outsider <outsideris@gmail.com>

Author: outsideris

.github/workflows/stale.yml

@@ -8,7 +8,7 @@ jobs:
   stale:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/stale@v4
+      - uses: actions/stale@v6
         with:
           days-before-stale: 120
           days-before-close: 14