As part of
SERVER-55376, we will be banning replica set reconfigs that try to go from a PA set to a PSA set where the secondary is electable in the new config since that is unsafe. Instead we should implement a shell helper to do the two back to back reconfigs proposed in WRITING-7727.
Legacy shell implementation: https://github.com/mongodb/mongo/blob/3192123cbc96d4c8121bd9849e70fd8b79eb37a9/src/mongo/shell/utils.js#L1572-L1619
Legacy shell tests: https://github.com/mongodb/mongo/blob/3192123cbc96d4c8121bd9849e70fd8b79eb37a9/jstests/noPassthrough/reconfig_for_psa_set_shell.js