Fix multipass Bash completion to work with ZSH

multipass.zsh

MULTIPASS="/snap/multipass/current/etc/bash_completion.d/snap.multipass"
if [[ -e "${MULTIPASS}" ]]; then
  source <(
    sed \
      -e '/_get_comp_words_by_ref/d' \
      -e 's^\$(echo \${BASH_VERSION} | .*)^0^' \
      "${MULTIPASS}"
  )
fi