release steps: fastforward main

meta/releasing.md

@@ -41,7 +41,7 @@ release.
 5. Push the release branch and the tag.
 6. GitHub Actions will run its build steps. Wait until these are successful. If fixes
    need to be made to repair the pipeline or spec build, delete and re-tag the release.
-7. Check out `main`.
+7. Check out and fast-forward `main` to the release branch.
 8. Generate the changelog. This is done *after* the tagging to ensure the rendered
    changelog makes sense.
    1. Activate your python virtual environment.