D9 Upgrade Issue with hook_removed_post_updates()

Problem/Motivation

I'm trying to upgrade from D8.9.x to D9.2.

Steps to reproduce

1. Got all modules D9 compatible
2. Followed steps 1, 2, 3, and 5 (skipped 4) under Upgrading a Composer-based Drupal 8 site in https://www.drupal.org/docs/upgrading-drupal/upgrading-from-drupal-8-to-...
3. Got the following errors from drush updatedb:

   •   In UpdateRegistry.php line 124:                                                               
                                                                                                     
         The following update is specified as removed in hook_removed_post_updates() but still exists in the code base: system_post_update_layout_plugin_schema_change 

   •   In UpdateRegistry.php line 124:                                                               
                                                                                                     
         The following update is specified as removed in hook_removed_post_updates() but still exists in the code base: system_post_update_entity_reference_autocomplete_match_limit 

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet