Fix two tiny bugs in the conformance suite

[AlexWaygood]

Mypy emitted an error, as expected, on line 39 of conformance/tests/aliases_recursive.py. But it wasn't emitting an error for the right reason -- the t6 variable here shadows a previously declared t6 variable on the previous line.

And on line 75 of conformance/tests/enums_members.py, the self is Pet.CAT condition will always evaluate to True, because this is a method on the Pet4 class, not the Pet class.