With Ubuntu Upgrade to Ubuntu 20.04 Postgres was updated to 12.
I did remove Postgres 12 with
sudo apt-get purge postgresql-12
to go back to Postgres Version 9.3 (I know it's outdated and upgrade highly recommended and it's planned within a few weeks)
But I noticed psql is still on version 12.2.
How can I revert psql version to 9.3?