Instalé un nuevo bash a través de brew
brew install bash
which bash # /opt/homebrew/bin/bash
chsh -s /opt/homebrew/bin/bash
He añadido /opt/homebrew/bin/bash
a /etc/shells
$ bash --version
GNU bash, version 5.1.8(1)-release (aarch64-apple-darwin20.4.0)
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
sin embargo, en la terminal, todavía me quedo en bash3.2.
echo ${BASH_VERSION} # still being 3.2.57(1)-release