Upgrade 12 to 13

prepare

sudo tee /etc/apt/apt.conf.d/90-noninteractive <<'EOF'
Dpkg::Options {
  "--force-confdef";
  "--force-confold";
};
EOF

export DEBIAN_FRONTEND=noninteractive
export NEEDRESTART_MODE=a
apt update -y --allow-releaseinfo-change
apt full-upgrade -y
apt --purge autoremove -y
reboot

change

sed -i 's/bookworm/trixie/g' /etc/apt/sources.list

update

apt update -y

upgrade step #1 - miniml upgrade upfront

apt upgrade --without-new-pkgs -y

upgrade step #2 - full upgrade

apt full-upgrade -y

reboot

reboot

clean up

sudo apt --purge autoremove
sudo apt clean