TermSelection is not working with Drupal 9.2

The TermSelection field is not saving the Target vocabulary and the field is empty if form widget is 'Select' or 'Check boxes/Radio buttons'. It looks like this is because the class is still using the handler_settings configuration (which was deprecated in 8.4. See https://www.drupal.org/node/2870971).

The module needs to do something like to get the configurations.

    // The ['handler_settings'] was removed on Drupal 8.4. the code below is
    // kept for back compatibility.
    // @see https://www.drupal.org/node/2870971
    $handler_settings = isset($this->configuration['handler_settings']) ? $this->configuration['handler_settings'] : $this->configuration;