`comment-on-alert` seems to be commenting even if there was no alert

My intention, to make PRs less verbose, is to get a benchmark-action comment *only* if there's an alert. That's why I have `comment-always: false` and `comment-on-alert: true` with `alert-threshold: 150%`.

However even though all the ratios were less than 1.5, I got the `github-actions` [comment here](https://github.com/sequentech/strand/pull/35#commitcomment-77799408). This is the [execution that triggered it](https://github.com/sequentech/strand/runs/7210386268?check_suite_focus=true#step:7:1).