Thanks for the patch. Patch applies cleanly and there are no errors for recto...

Thanks for the patch. Patch applies cleanly and there are no errors for rector and drupal check.

Please update the core_version_requirement in info.yml as well.

modules/custom/blocktabs/blocktabs.info.yml Add core_version_requirement: ^8 || ^9 to modules/custom/blocktabs/blocktabs.info.yml to designate that the module is compatible with Drupal 9. See https://drupal.org/node/3070687.