Deleting a field that uses a permission_callback does not delete the permission

Using the instructions from the test module. If you add field.field.node.article.field_stillthere as a config dependency in the role you at least get a warning when you delete the file.

I did some digging and the way this is handled for node bundles in core is that a dependencies key is added to the permissions array declaring the dependency on the node bundle like this:

dependencies:
  config:
    - node.type.article

The dependencies key is added via trait Drupal\Core\Entity\BundlePermissionHandlerTrait which in turn calls these methods:

Drupal\Core\Entity\EntityInterface::getConfigDependencyKey() // returns 'config' for a node bundle
Drupal\Core\Entity\EntityInterface::getConfigDependencyName() // returns 'node.type.<BUNDLE>' for a node bundle

So I guess the correct way to solve this issue is to add the dependencies key to the permissions array.

I'm attaching a patch for the Test delete field module just to make it clear what I mean.