This is *not* ki18n related, but related to the modules we have that use the Qt translation system like kcoreaddons.
There we use https://invent.kde.org/sysadmin/l10n-scripty/-/blob/master/extract-tr-strings to extract the strings to a .ts and then convert it to a .po files
The translators translate the .po files and then we use https://invent.kde.org/frameworks/extra-cmake-modules/-/blob/master/modules/ECMPoQmTools.cmake to convert them back to .qm so they can be used by the Qt translation system.
The first extraction/conversion part is done by scripty and at this moment it unconditionally uses Qt5 variants of lconvert/lupdate.
Would be good to know if we can keep using those or if we need to use the Qt6 variants of lconvert/lupdate in scripty.