This is a trivial change but conceptually a milestone.
This is targeted to be complete for the MediaWiki 1.34 release.
Required testing: update.php must work correctly after this change is implemented.
This epic cannot begin until T231671 is complete. Ideally, this epic should not begin until T231672 is complete.
- in DefaultSettings.php, set $wgMultiContentRevisionSchemaMigrationStage = SCHEMA_COMPAT_NEW;