feat(linear_algebra/finsupp): A variant of `finsupp.total` for `fintype`s. (#15462)
feat(linear_algebra/finsupp): A variant of `finsupp.total` for `fintype`s. (#15462)




Co-authored-by: Andrew Yang <5a6b17dbbc661dec6b250b080ab0033de7d56af5@users.noreply.github.com>

leanprover-community/mathlib,leanprover-community/mathlib