Improved query in AbandonedCarts::getAbandonedOrders() method

I'm not sure if the failed tests are related to the changes, but I've added changes to the query to use the 2.x commerce way.

The test failures only look like to happen for Drupal 11 + Commerce 3.x. Maybe something changed in Commerce 3.x recently that caused the tests to fail?

Is it enough to only test for mail to be not null or can it be an empty string too?

I see that the recent change is noted on the release on the Commerce Core project page:

The cart module no longer depends on commerce_product.

So I think that in the tests we need add a to dependency to 'commerce_product'. I shall create a new issue for that.

I fixed the branch tests in 📌 Fix tests for Drupal 11 / Commerce 3.x Active and then I merged 2.1.x into this issue fork. Let's see what that does for the tests.

All tests are passing after fixing a few other issues first!

Test coverage for Commerce Recurring would be a nice to have, but we could also handle that in an other issue. I don't use Commerce Recurring, so I do not plan to write these tests myself.

Then we may need to answer the following question still: is it enough to only test for mail to be not null or can it be an empty string too?