The main reason for doing this is to have some common code between scripts, so that it is easier to change the JSON schema globally and normalize a few things (such as release order).
The Ruby code was kept as is so we can quickly roll back if necessary.
The script only get versions 4.x and above, see script comments for more informations.
Note that the code related to git has been extracted to a common script so that it can be reused for the Debian script.