In PostgreSQL, FOREIGN KEY and CHECK constraints allows the NOT VALID
option to ADD table constraint in ALTER TABLE statement.

https://www.postgresql.org/docs/current/sql-altertable.html#SQL-ALTERTABLE-DESC-ADD-TABLE-CONSTRAINT

Fortunately, foreign keys are not dumped as part of `create_table` so
the ALTER TABLE specific options are restored correctly.

CHECK constraints are a feature supported by all adapters, but NOT VALID
is a PostgreSQL-specific option, so only NOT VALID constraints are
dumped as ALTER TABLE statements so as not to affect the behavior of
other adapters.

Fixes #53732.