fix: Prevent customer deletion failure when customer language is missing from sales channel

fix: Prevent customer deletion failure when customer language is missing from sales channel: a task in bird-critic-1.5-full-300 (Harbor dataset). CustomerBeforeDeleteSubscriber fires a CustomerDeletedEvent before a customer is removed. To build event context it calls…

The task

`CustomerBeforeDeleteSubscriber` fires a `CustomerDeletedEvent` before a customer is removed. To build event context it calls `SalesChannelContextService::get()` with the customer's language ID. If that language has since been removed from the sales channel's language list, the context service throws a…

Part of kochsnow/bird-critic-1.5-full-300.