Recommendation is to avoid using the year nomenclature as this
information is already encoded in the git repo. Avoids needing to
repeatly update.
Also updates AUTHORS.txt from current repo with contributor names
Makes a test backup file and compares to the existing zip file backup to
see if the files have changed since it was made. If so, the new file is
kept. If not, we discard the new file and continue
Fixes https://gitlab.com/kicad/code/kicad/-/issues/12453
