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.
Create a common function to write resulting JSON files to the releases directory.
It makes this task simpler to read and maintain, while making it modifiable at a central point in the future.
One example of such modification could be the sorting of the versions in a uniform way for all the scripts.
