Config entities implementing EntityWithPluginCollectionInterface should ask the plugins to react when their dependencies are removed

Related, with 162 followers: 💬 Drupal 10 updating issue - Drupal\Component\Plugin\Exception\PluginNotFoundException: The "" plugin does not exist Needs work .

Created MR 13171 with a new approach that is mostly based on the MR for 🐛 Deleting a Media view mode should not result in the deletion of an entire text format Active , combined with some ideas from the patch in #70:

1. Add new interface Drupal\Core\Plugin\RemovableDependentPluginInterface with method onCollectionDependencyRemoval()
2. Add code in ConfigEntityBase::onDependencyRemoval() that tests if the entity implements EntityWithPluginCollectionInterface. If so, iterate through collections and if there are plugin that implement RemovableDependentPluginInterfacedependencies::onCollectionDependencyRemoval(), invoke the method on that plugin so it can react by changing its configuration or removing itself from the collection
3. If onCollectionDependencyRemoval() returns TRUE, then ConfigEntityBase::onDependencyRemoval() will return TRUE, so the config entity's dependencies can be recalculated
4. Implement two use cases: 1) prevent image styles from being deleted if a module that provides any of its image effects is uninstalled and 2) prevent filter formats from being deleted if a media entity view mode used in a media embed filter is deleted
5. Add kernel tests for two use cases

This approach kind of comes at the problem from the other way of the patch. The handling of the dependency removal is done completely in the plugin class, other than the entity invoking the plugin's onCollectionDependencyRemoval() method. The plugin collection and index ID of the plugin instance in the collection are provided as arguments along with the dependencies, so that the plugin instance can be removed from the collection as needed. This approach is kind of based on how Drupal\views\Entity\View\onDependencyRemoval() invokes DependentWithRemovalPluginInterface::onDependencyRemoval() for handler plugins, as well as FieldItemInterface::onDependencyRemoval(), which has the field definition object as well as the dependencies passed in.

There may need to be tests added to test the dependency removal handling generically. The tests in the MR are kernel tests specific to the the image style and media view mode use cases. The unit tests in #70 no longer apply to the solution.

Also bumping this to critical, because 🐛 Deleting a Media view mode should not result in the deletion of an entire text format Active combined with 📌 Deleting filter formats may result in data loss Active can lead to content data loss. There is a case of this actually happening brought up in slack: https://drupal.slack.com/archives/C1BB308HH/p1755719629686569

Also, with this 🐛 Deleting a Media view mode should not result in the deletion of an entire text format Active is effectively a duplicate, so it perhaps can be closed with credits transferred here.

Changed the functional test for media to a kernel test, and added a unit test for more generic coverage.