Attributes fixes and warning removal

- when the payments array was folded into sale_data there was an earlier payments[] reference in the foreach loop that didn't get folded in.
- Update PHPdoc
- Added ::class to remove polymorphic call warning
- Removed unreachable 'break;' statement after return statement.
- Added missing return type
- fixed missing assignment of mailchimp_api_key
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f