argon2 to be used, by default, it will automatically choose the best available
algorithm depending on which version of PHP you have available. To use this,
you can set `$wgPasswordDefault = 'argon2';`.
+* $wgActorTableSchemaMigrationStage now defaults to reading the new schema.
+ update.php will back-populate the new database fields due to the changed
+ setting, which may take some time on large wikis. You can avoid downtime by
+ following a process like that described in T188327.
==== Removed configuration ====
* $wgTagStatisticsNewTable (T199334) — This temporary setting, added in