README.md: update leaderboard

commit generated automatically from
https://github.com/fxnn/adventofcode2024/actions/runs/12458501283

Author: fxnn

README.md

@@ -5,7 +5,7 @@ See https://adventofcode.com/2024
 
 [//]: # (LEADERBOARD_BEGIN)
 
-> ![19 stars](https://img.shields.io/badge/19-%E2%AD%90_stars-gold) <br /> user **fxnn** (last one at 2024-12-22T16:46:10Z)
+> ![20 stars](https://img.shields.io/badge/20-%E2%AD%90_stars-gold) <br /> user **fxnn** (last one at 2024-12-22T23:18:03Z)
 
 [//]: # (LEADERBOARD_END)