This is a bug and it’s introduced in the new version of PhpStorm.
It’s not possible to disable the warning since it’s an annotator inspection. I also don’t recommend changing your code for the sole purpose of fixing this warning since it’s an IDE bug and will be addressed in their next patch. If it’s not really causing any breaking side effects, just wait until the patch is released!
Update
This bug has been fixed in PhpStorm 2020.3.1.