mathlib3

bf1465c2 - refactor(data/fintype/basic): golf `card_eq_one_of_forall_eq` (#6131)

refactor(data/fintype/basic): golf `card_eq_one_of_forall_eq` (#6131) Co-authors: `lean-gptf`, Stanislas Polu This was found by `formal-lean-wm-to-tt-m1-m2-v4-c4` when we evaluated it on theorems added to `mathlib` after we last extracted training data.