It was, of course, an AI-generated solution; they posted it here: https://web.archive.org/web/20241201052156/https://github.co...

Later, after being called out on it, they posted an apology to their GitHub profile (https://web.archive.org/web/20241201064816/https://github.co...): "If you are here from the AoC leaderboard, I apologize for not reading the FAQ. Won't happen again."

Both the repo and that message are now gone.