While switching from isoImage.baseName to the unified image.baseName,
I accidentaly dropped label and system information from the iso filename.
This fixes it by including isoImage.edition in the default baseName for
all our isos. Resulting in filenames such as
`nixos-minimal-25.05beta708350.1d95cb5-x86_64-linux.iso` again instead
of just nixos-minimal.iso.
0b162c3dbc