[LyX/master] Update generate contributions to Python 3+

[José Matos]

commit aeee6b373ea454a5d570c87f851de055db020a94
Author: José Matos <jamatos at lyx.org>
Date:   Mon Jun 10 11:43:04 2024 +0100

    Update generate contributions to Python 3+

 lib/generate_contributions.py | 1111 ++++++++++++++++++++---------------------
 1 file changed, 545 insertions(+), 566 deletions(-)