With the change from github.event.inputs to inputs, and booleans being actual booleans. We could re-introduce the (partially correct) behavior from before:

${{ inputs.dry_run && '--dry-run' || '' }}

Note the added || '' which is required to avoid outputting false.

Booleans should now work, and snapshot has been removed to simplify slightly.

In the future. Let's rewrite this so that one workflow produces release notes and creates and pushes the tag. And that in turn triggers this workflow to produce the actual release.