[#711] restore balancing del statement.

An object, referenced as cls.logins in the setUpClass method of some of the
test classes, was delayed too much in its destruction, which in earlier Python releases
(3.8 and 3.9, at least) prevented proper test cleanup.

Author: d-w-moore

irods/test/collection_test.py

@@ -35,7 +35,10 @@ def setUpClass(cls):
 
     @classmethod
     def tearDownClass(cls):
-        # TODO(#553): Skipping this will result in an interpreter seg fault for Py3.6 but not 3.11; why?
+        # As in Python 3.8 and previous, Python 3.9.19 will react badly to leaving out the following del statement during test runs. Although
+        # as of 3.9.19 the segmentation fault no longer occurs, we still get an unsuccessful destruct, so the __del__ call in cls.logins
+        # fails to do all of the work for proper test teardown. This happens because the object is being garbage collected at a point in time
+        # when the Python interpreter is finalizing.
         del cls.logins
 
     def setUp(self):

irods/test/data_obj_test.py

@@ -917,7 +917,11 @@ def setUpClass(cls):
 
     @classmethod
     def tearDownClass(cls):
-        pass
+        # As in Python 3.8 and previous, Python 3.9.19 will react badly to leaving out the following del statement during test runs. Although
+        # as of 3.9.19 the segmentation fault no longer occurs, we still get an unsuccessful destruct, so the __del__ call in cls.logins
+        # fails to do all of the work for proper test teardown. This happens because the object is being garbage collected at a point in time
+        # when the Python interpreter is finalizing.
+        del cls.logins
 
     def _data_object_and_associated_ticket(
         self,