Remove timeout-minutes from lock-closed-issues workflow

The 10-minute timeout is unnecessary for this workflow as it typically
completes quickly. Removing it allows the workflow to use the default
GitHub Actions timeout (6 hours for public repos, 72 hours for private),
providing more flexibility if the workflow needs to process a large
number of issues.

Also fixed trailing whitespace inconsistencies in the script.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/lock-closed-issues.yml

@@ -15,7 +15,6 @@ concurrency:
 jobs:
   lock-closed-issues:
     runs-on: ubuntu-latest
-    timeout-minutes: 10
     steps:
       - name: Lock closed issues after 7 days of inactivity
         uses: actions/github-script@v7