Fix another typo in janitor GHA

PiperOrigin-RevId: 560173228

.github/workflows/janitor.yml

@@ -10,8 +10,10 @@ jobs:
   stale-prs:
     name: Close Stale Copybara PRs
     runs-on: ubuntu-latest
+    env:
+      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
-      run: |
+      - run: |
           set -ex
           STALE_PRS=$(gh pr list --author "app/copybara-service" --limit 500 \
               --json "number" --search "updated:<=$(date --date="-7 day" +%F)" \
@@ -20,5 +22,3 @@ jobs:
             echo "Closing #$pr..."
             gh pr close --comment "Auto-closing Copybara pull request" --delete-branch "$pr"
           done
-      env:
-        GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}