v8.21

- dietpi-bookworm-upgrade | Mark all packages unhold before touching list files. If hold packages are not available anymore afterwards, they remain as dummy entries in "status" and "available" DPKG databases to preserve their hold state. At the same time, "apt-mark unhold" cannot be performed on packages which are neither installed nor available in any installed APT list/repo: #6559

.meta/dietpi-bookworm-upgrade

@@ -50,6 +50,10 @@ G_CHECK_KERNEL || { G_WHIP_YESNO '[ INFO ] Reboot required
 G_DIETPI-NOTIFY 2 'Updating DietPi to latest version'
 /boot/dietpi/dietpi-update 1
 
+mapfile -t apackages < <(apt-mark showhold)
+[[ ${apackages[0]} ]] && G_EXEC_DESC='Unholding all packages' G_EXEC apt-mark unhold "${apackages[@]}"
+unset -v apackages
+
 G_DIETPI-NOTIFY 2 'Migrating package lists to Bookworm suite'
 G_EXEC sed -i -e 's/bullseye/bookworm/g' -e 's/ non-free$/ non-free non-free-firmware/' /etc/apt/sources.list
 [[ $(find /etc/apt/sources.list.d/*.list 2> /dev/null) ]] && G_EXEC sed -i 's/bullseye/bookworm/g' /etc/apt/sources.list.d/*.list