Release notes: enhance the workflow to take an optional argument specifying the target version (1.2.3 vs. 1.3.0 ...) and/or whether this is a minor or major release

[fingolfin]

... namely the optional argument for the release notes script...

See e.g. https://github.com/gap-system/PackageDistro/blob/main/.github/workflows/scan-for-updates.yml for a workflow I maintain that also accepts an optional argument