--target-version involving Python 2 picks the wrong grammar

--target-version involving Python 2 picks the wrong grammar: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). I maintain a library that still supports Python 2.7 alongside Python 3, and I was excited to try Black's --target-version flag to lock the formatting to my…