chinese/ibus-libpinyin: update to 1.15.2

• update LICENSE
• STROKE removed, new TABLE

Changelog: https://github.com/epico/ibus-libpinyin/compare/1.11.1...libpinyin:ibus-libpinyin:1.15.2

PR: 270156
Approved by: Henry Hu <henry.hu.sh@gmail.com> (maintainer)