Issue #3224861 by Spokje: PHPCS failure in /core/modules/tour/src/TourViewBuilder.php

          // TourTipPluginInterface. This means the tour tip must be constructed

          // with the deprecated getOutput() method. The resulting tour tip

          // should be largely identical, with the following exceptions:

          // 1 - If the tour tip `attributes` property included anything other

          // - If the tour tip `attributes` property included anything other

          //   than `data-class` or `data-id`, these additional attributes

          //   will not be available in the resulting tour tip. Note that such

          //   uses are uncommon.

          // 2 - Although the tour tip content is identical, the markup

          //     structure will be different due to being rendered by Shepherd

          //     instead of Joyride. Themes extending Stable or Stable 9 will

          //     not experience these changes as a script is provided that

          //     reconstructs each tip to match Joyride's markup structure.

          // - Although the tour tip content is identical, the markup structure

          //   will be different due to being rendered by Shepherd instead of

          //   Joyride. Themes extending Stable or Stable 9 will not experience

          //   these changes as a script is provided that reconstructs each tip

          //   to match Joyride's markup structure.

          $attributes = (array) $tip->get('attributes');

          if (array_diff(['data-class', 'data-id'], array_keys($attributes + ['data-class', 'data-id']))) {

            trigger_error('The tour tips only support data-class and data-id attributes and they will have to be upgraded manually. See https://www.drupal.org/node/3204093', E_USER_WARNING);