transformers

cecacd37 - Fix `KeyError` when patching mistral regex (#43376)

Fix `KeyError` when patching mistral regex (#43376) * Avoid multiple fix_mistral_regex (KeyError) * add regression test * style * fix --------- Co-authored-by: Leonardo Emili <lemili@apple.com> Co-authored-by: vasqu <antonprogamer@gmail.com>