Queued files in key-value store are not properly deleted

In ExtractorQueue::processItem(), when extraction of the file contents succeeds, this happens:

      $fallback_collection = $this->keyValue->get(FilesExtractor::FALLBACK_QUEUE_KV);
      $fallback_collection->delete($data->entity_type . ':' . $data->entity_id);

However, that is not the structure of that collection, in FilesExtractor::queueItem() values are added like this:

      $queued_file_collection = $this->keyValue->get(static::FALLBACK_QUEUE_KV);
      $queued_files = $queued_file_collection->get($file->id());
      $queued_files[$entity->getEntityTypeId()][$entity->id()] = TRUE;
      $queued_file_collection->set($file->id(), $queued_files);

Therefore, it seems to me like entries will stay indefinitely in this fallback queue collection.

PS: I cannot set “10.0.x-dev” as the version as there is no dev snapshot release for that yet.