Choisir le ppa générique https://doc.ubuntu-fr.org/libreoffice#versions_stables
et puis apt full-upgrade.

Ce qui donne :

• sudo add-apt-repository ppa:libreoffice/ppa
• sudo apt update
• sudo apt full-upgrade

Don’t worry about the full-upgrade option. The apt full-upgrade variant “performs the function of upgrade but will remove currently installed packages if this is needed to upgrade the system as a whole”.