⬆️ Update dessant/lock-threads action to v6

Author: renovate[bot]

.github/workflows/lock.yaml

@@ -12,7 +12,7 @@ jobs:
     name: 🔒 Lock closed issues and PRs
     runs-on: ubuntu-latest
     steps:
-      - uses: dessant/lock-threads@v5.0.1
+      - uses: dessant/lock-threads@v6.0.0
         with:
           github-token: ${{ github.token }}
           issue-inactive-days: "30"