Alternative preview release flow

[emmatown]

Example run: https://github.com/emmatown/changesets-action/actions/runs/25488677177

Note I've done this from a fork of this repo, not on changesets/action itself, this is partly because GitHub won't let you trigger the workflow dispatch unless the workflow exists on main and partly to demonstrate how it works on a fork.

[changeset-bot]

⚠️ No Changeset found

Latest commit: cedecbb

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR