use error.Is to check for nondeterminstic vote error type (#6237) (#6239)
use error.Is to check for nondeterminstic vote error type (#6237) (#6239)

(cherry picked from commit bf8cce83db15ee2645924799a4b2dfba260788dc)

Co-authored-by: Callum Waters <5f72b908d85391e7f21a84deb028d535a0c28a75@gmail.com>
tendermint/tendermint,tendermint/tendermint,tendermint/tendermint,tendermint/tendermint