Suggest that maintainers make small fixes directly before merging

If a merge request is done, but has a trivial change needed (for instance, a typo fix), then it's much more efficient if the maintainer does that directly using the suggest changes feature:

1. It prevents another back and forth, especially where the maintainer and author are in different time zones.
2. It saves a pipeline run if the maintainer doesn't see the new MR within two hours of the new pipeline running.

Based on a short thread in #backend_maintainers, it appears a few of us are already doing this.