This way the writing of the JSON file is handled automatically if the update does not fail.
It pave the way to further global improvements, such as a better error handling.
It may not be the best place for that (gha.py would have been better), but it's the shorter / faster way to do it for now.
Moreover it now uses logging for writing the group. The logger format has been updated for this to work. This was done to fix issues on GitHub Action logs, where groups were declared after the logs.
Make the script more readable, mostly by:
- using the endoflife.Product class,
- removing some unnecessary use of functions,
- a little bit of renaming and documentation.
