patch 9.0.1399: highlight test script has a few problems Commit: https://github.com/vim/vim/commit/4df0772a41c361a1c40d220f6fad0b1e1653fc5b Author: lagygoill <lacygoill@lacygoill.me> Date: Fri Mar 10 18:37:11 2023 +0000 patch 9.0.1399: highlight test script has a few problems Problem: Highlight test script has a few problems. Solution: Rewrite the script in Vim9 syntax. (closes https://github.com/vim/vim/issues/10379)