Hibernate 6 fails to refresh when collections are accessed in entity setter method when access type is property

We are having issues with complex @OneToMany relationships. See attached repository, which demonstrates the problem:

https://github.com/knyttl/Hibernate5vs6Test

The repo has HIbernate 5 in pom.xml, so when running the test as:

```bash
mvn test -Dhibernate.server={my-server} -Dhibernate.database={my-database} -Dhibernate.password={my-password} -Dhibernate.user={db-user}
```

You will see the test is *correctly passing*, logs here: https://gist.github.com/knyttl/ac8010f853bc22b1a0176e856cad0a3e

Now please uncomment Hibernate 6 in `pom.xml` and run the test again.

The test will now fail with this log: https://gist.github.com/knyttl/292aeb613fd10b9c9fbf8d7b5d7e2073