Publish core/light images as part of releases

[mudler]

trafficstars

Is your feature request related to a problem? Please describe. Currently core and light images are only published from master builds

Describe the solution you'd like releases with only the c3os version number, containing core/light assets (iso, netboot artifacts, etc)

Describe alternatives you've considered

Additional context

[mudler]

This is done already, just needs a test release, but the same workflows were reused