BUG: failing test_hierharchy_arraylist with jdk>=21

[h-vetinari]

When building pyjnius 1.6.1 against newer openjdk (21, 22) in conda-forge, things compile and run fine, with the exception of one test failure:

=================================== FAILURES ===================================
____________________ ReflectTest.test_hierharchy_arraylist _____________________

self = <test_reflect.ReflectTest testMethod=test_hierharchy_arraylist>

    def test_hierharchy_arraylist(self):
        d = identify_hierarchy_dict(find_javaclass("java.util.ArrayList"), 0, True)
        self.assertContains(d, "java.util.ArrayList")# concrete
        self.assertContains(d, "java.util.AbstractCollection")# superclass
        self.assertContains(d, "java.util.Collection")# interface
        self.assertContains(d, "java.lang.Iterable")# interface
        self.assertContains(d, "java.lang.Object")# root
        maxLevel = max(d.values())
>       self.assertEqual(d["java.lang.Object"], maxLevel)
E       AssertionError: 3 != 4

tests/test_reflect.py:38: AssertionError
=========================== short test summary info ============================
FAILED tests/test_reflect.py::ReflectTest::test_hierharchy_arraylist - AssertionError: 3 != 4
======================== 1 failed, 164 passed in 0.94s =========================

It seems all the expected hierarchy levels are still there, but either the hierarchy itself changed for real (meaning the test expectation is wrong), or the calculation in identify_hierarchy_dict needs to fix something to take into account the new reality.