Postgres 15 upgrades and template1 public schema

[Bruno Wolff III]

I noticed when I did an upgrade from Postgres 14 to 15 that the public 
schema in template1 was still owned by postgres instead of pg_database_owner. 
I was expecting it to change because the release notes said that new 
database clusters would have that. But shouldn't new clusters use what 
is set in template1?