Error: FATAL: no pg_hba.conf entry for host - PostgreSQL - pg_hba.conf is empty
Upgrading a database with either dump/restore or pg_upgrade will not copy the configuration files, so you are left with whatever pg_hba.conf was there right after initdb created the new cluster.

You have to edit and adapt postgresql.conf and pg_hba.conf and other configuration files you use manually on the new cluster. With pg_hba.conf copying the file over is usually good enough, but postgresql.conf requires more attention.