drupal8 and drupal9 fail with php ./drush/platformsh_generate_drush_yml.php

[rfay]

When drupal8 and drupal9 templates get to

php ./drush/platformsh_generate_drush_yml.php they fail on ddev start with

$ php drush/platformsh_generate_drush_yml.php
Failed to find a site URL

Note that since DDEV doesn't need a drush.yml this may not be that relevant, but it would be better if it worked.

[rfay]

This problem has been resolved by changes over time, probably PLATFORM_RELATIONSHIPS or PLATFORM_ROUTES