Dbal error stopping NC20 to 21 upgrade

When trying to update to 21.0.7, I’ve hit the error below. I’ve tried the web updater, cli, and a manual upgrade.

OC\DB\Exceptions\DbalException: Unknown column type “json_array” requested. Any Doctrine type that you use has to be registered with \Doctrine\DBAL\Types\Type::addType(). You can get a list of all the known types with \Doctrine\DBAL\Types\Type::getTypesMap(). If this error occurs during database introspection then you might have forgotten to register all database types for a Doctrine Type. Use AbstractPlatform#registerDoctrineTypeMapping() or have your custom types implement Type#getMappedDatabaseTypes(). If the type name is empty you might have a problem with the cache or forgot some mapping information.

Preparing update
Set log level to debug
Turned on maintenance mode
Repair step: Repair MySQL collation
Repair info: All tables already have the correct collation -> nothing to do
Repair step: Repair SQLite autoincrement
Repair step: Copy data from accounts table when migrating from ownCloud

OC\DB\Exceptions\DbalException: Unknown column type "json_array" requested. Any Doctrine type that you use has to be registered with \Doctrine\DBAL\Types\Type::addType(). You can get a list of all the known types with \Doctrine\DBAL\Types\Type::getTypesMap(). If this error occurs during database introspection then you might have forgotten to register all database types for a Doctrine Type. Use AbstractPlatform#registerDoctrineTypeMapping() or have your custom types implement Type#getMappedDatabaseTypes(). If the type name is empty you might have a problem with the cache or forgot some mapping information.

I’d be more than happy provide more information about my setup, but am not sure what’d be valuable to have offhand.