BUG #18242: pg_dump with non-superuser from pg14 to pg15 fails on ALTER FUNCTION

The following bug has been logged on the website:

Bug reference:      18242
Logged by:          Aksel Allas
Email address:      aksel.allas@pactum.com
PostgreSQL version: 15.5
Operating system:   Debian/GNU Linux 12
Description:

Please see
https://github.com/AkselAllas/pg_dump-alter-function-problem-with-non-superuser
for reproduction steps in dockerized environment.

The gist is that:

When making a dump from PostgreSQL 14 and using it in PostgreSQL 15 with a
user that has no superuser access (e.g. cloud environments), then we run
into the following line from
https://www.postgresql.org/docs/15/sql-alterfunction.html

> To alter the owner, you must also be a direct or indirect member of the
new owning role, and that role must have CREATE privilege on the function's
schema.