fix(setup): ensure PostgreSQL 18 compatibility (#11484)

# Which Problems Are Solved

When starting Zitadel with Postgres version 18, setup fails with the
following error:

`level=error msg="migration failed" caller=".../cmd/setup/setup.go:373"
code=0A000 detail= error="ERROR: partitioned tables cannot be unlogged
(SQLSTATE 0A000)" hint= message="partitioned tables cannot be unlogged"
name=34_add_cache_schema severity=ERROR`

# How the Problems Are Solved

- Modify setup step 34 to ensure compatibility with PostgreSQL 18 by
changing the creation of the partitioned tables to`LOGGED` tables but
keep the partitions `UNLOGGED`.
- Added an additional setup step which alters the table persistence of
the partitioned tables to `LOGGED`.

# Additional Changes

- Bumped Postgres compatibility to version 18 in docs.
- Ensure default partitions for cache tables

## Additional Context

- closes https://github.com/zitadel/zitadel/issues/10712
- backport to v4
- migration from PostgreSQL version 17 to 18 was verified using
`pg_dumpall` and restoring the created backup file
- and new setups using PostgreSQL version 18 directly

---------

Co-authored-by: Copilot <[email protected]>

apps/docs/content/self-hosting/manage/database/_postgres.mdx

@@ -4,7 +4,7 @@ PostgreSQL is the default database for ZITADEL due to its reliability, robustnes
 
 If you are using Zitadel v2 and want to use a PostgreSQL database, you can [overwrite the default configuration](/self-hosting/manage/configure/configure).
 
-Currently, versions 14 to 17 are supported.
+Currently, versions 14 to 18 are supported.
 
 Postgres can be configured as follows:
 ```yaml