bpo-34997: Fix test_logging.ConfigDictTest.test_out_of_order (GH-9913)

When runnint test_logging with --huntrleaks after commit
18fb1fb943b7dbd7f8a76017ee2a67ef13effb85, test_out_of_order fails
to raise ValueError due to the fact that the new test
test_out_of_order_with_dollar_style mutates the out_of_order
dictionary. Even if the test copies the dictionary first, the mutation
is done in a very deep level so the original one is also affected.