Permission to alter the content of system tables

I need to alter the content of the

pg_catalog.pg_class

pg_catalog.pg_class

table to replace

reltuples

reltuples

and

relpages

relpages

with custom values (yeah, it's a strange need but my project depends on it). On a local Docker PostgreSQL instance, I can run

ALTER USER my_user WITH SUPERUSER

ALTER USER my_user WITH SUPERUSER

, which allows me to create a function with

SECURITY DEFINER

SECURITY DEFINER

that has permission to modify system tables. How can I do something similar with Neon? Thanks