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
Note that I don't have any data that the global var hack was causing
the bug, so this may or may not fix it. But it seems as good a candidate
as any.
Fixes https://gitlab.com/kicad/code/kicad/issues/12871
