Enhance bookworm setup.

[config] / update_key.sh

#!/bin/sh
set -e

if [ "$#" -ne 1 ]; then
  echo "Need exactly one argument: public key ID."
  false
fi
gpg_key="$1"
keyservers='keyserver.ubuntu.com pgp.surf.nl pgp.rediris.es'
set +e
for keyserver in $(echo "${keyservers}"); do
    gpg --no-tty --keyserver $keyserver --send-key "${gpg_key}"
done
set -e