Remove, from stable branches, the new assertion of no pg_dump OID sort.

Remove, from stable branches, the new assertion of no pg_dump OID sort.

Commit 0decd5e89db9f5edb9b27351082f0d74aae7a9b6 recently added the
assertion to confirm dump order remains independent of OID values.  The
assertion remained reachable via DO_DEFAULT_ACL.  Given the release wrap
tomorrow, make the assertion master-only.

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/d32aaa8d-df7c-4f94-bcb3-4c85f02bea21@gmail.com
Backpatch-through: 13-18