Make module compatible with PHP 8.3

I cannot reproduce it running D10.3 and PHP8.2.

I don't see duplicate variable declaration in the PHP class on the dev branch either.

Maybe you had a clash with a patch or this commit: https://git.drupalcode.org/project/domain_entity/-/commit/0b0b254c5bdd5b...

Hi @thejimbirch
I've faced with the same error after upgrading project to drupal11. Please check if you have any patches for domain entity module.