chore(deps): update actions/stale action to v6 (#14)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/prune.yaml

@@ -18,7 +18,7 @@ jobs:
 
     steps:
       - name: "Prune issues and pull requests"
-        uses: "actions/stale@v3.0.19"
+        uses: "actions/stale@v6.0.1"
         with:
           days-before-close: "${{ env.DAYS_BEFORE_CLOSE }}"
           days-before-stale: "${{ env.DAYS_BEFORE_STALE }}"