BUG #18281: Superuser can rename the schema with the prefix "pg_" (Applies to all versions of postgresql)

The following bug has been logged on the website:

Bug reference:      18281
Logged by:          Maciej Szeliga
Email address:      szyjek9302@gmail.com
PostgreSQL version: 16.1
Operating system:   centos 8
Description:

Hi, 
I renamed the schema pg_toast 
moja=# alter schema pg_toast rename to x_pg_toast
moja-# ;
ALTER SCHEMA

and can't undo it because :

moja=# alter schema x_pg_toast rename to pg_toast;
ERROR: unacceptable schema name "pg_toast"
DETAIL: The prefix "pg_" is reserved for system schemas.

I think this is a serious problem that should be fixed by developers. The
superuser should not be able to rename system schemas.

Regards
Maciej