Invalid mapping definition encountred with database updates for Drupal 10.3..0

This patch takes care of it and hopefully has the correct schema structure.

I see the error happens during the system_post_update_add_langcode_to_all_translatable_config update. Not sure if the expected schema structure changed at some point or if it's been broken all this time, but your changes seem to fix the issue on 10.3 without breaking anything on earlier versions, so. Merged into the new 2.x branch. Thank you!

Automatically closed - issue fixed for 2 weeks with no activity.