ArchaicUpperLowerPlugin not detecting case changes correctly

ArchaicUpperLowerPlugin not detecting case changes correctly: a task in harbor-swesmith-rl-artifacts: Harbor SWE-Smith 强化学习数据产物 (Harbor dataset). I've noticed that the ArchaicUpperLowerPlugin in charset normalizer is not correctly detecting case changes in text, which affects charset detection for…

The task

I've noticed that the ArchaicUpperLowerPlugin in charset_normalizer is not correctly detecting case changes in text, which affects charset detection for certain languages.

Part of keryszhan/harbor-swesmith-rl-artifacts.