Issue on removing the Commerce Recurring module

The site core needs to be updated from 8 to 9. Before updating, it was decided to remove the Commerce module and install it on an already updated core. Removal is carried out according to the instructions:
https://docs.drupalcommerce.org/commerce2/developer-guide/install-update...

Problems start when trying to remove the Commerce Recurring module. On the module removal page, the text "The Billing period field type is used in the following fields: commerce_order.billing_period, commerce_order_item.billing_period"/ appears in the corresponding module card. I found these fields, but they are in the Locked status.

I tried to prepare the removal of the Commerce Recurring module in the ways described here:
https://www.drupal.org/project/commerce_recurring/issues/2924965#comment... 🐛 [PP-1] Module does not uninstall cleanly (dependency issue) Postponed
https://www.drupal.org/project/drupal/issues/2871486#comment-13894528 🐛 field.storage YAML and FieldType plugin cannot coexist in same module because of FieldUninstallValidator constraint Needs work
but when I delete it, I get the following error:
Drupal\Component\Plugin\Exception\PluginNotFoundException: Unable to determine class for field type 'commerce_plugin_item:commerce_subscription_type' found in the 'field.storage.commerce_product_variation.subscription_type' configuration in Drupal\field\FieldStorageConfigStorage->mapFromStorageRecords() (line 174 of core/modules/field/src/FieldStorageConfigStorage.php).

When I try to update the Drupal Core from 8 to 9 using the following instructions ( https://www.drupal.org/docs/upgrading-drupal/upgrading-from-drupal-8-to-... → ) a message like below appears:
"- drupal/core-recommended 9.3.x-dev requires drupal/core 9.3.x-dev -> satisfiable by drupal/core[9.3.x-dev].
- Conclusion: don't install drupal/core 9.3.x-dev (conflict analysis result)"

Also, I was unable to get more information about Drupal 9 incompatibility with the current site settings.
Tried these methods:
1) points 3 and 4 from:
https://www.drupal.org/docs/upgrading-drupal/upgrading-from-drupal-8-to-... →
2) https://www.drupal.org/docs/develop/using-composer/using-drupals-lenient... →