How To: iteratively delete GH workflow runs:

I can remove the last 100 runs with gh cli:

```
gh run list --limit 100 --json databaseId --jq '.[].databaseId' | while read run_id; do echo "Deleting run $run_id..."; gh run delete "$run_id" 2>/dev/null && echo "✓ Deleted" || echo "✗ Failed"; done
```