gpython: tests: Don't verify -OO on PyPy2

PyPy2 implements -OO differently compared to CPython and it breaks zope.interfaces
at import time: https://foss.heptapod.net/pypy/pypy/-/issues/3356.

gpython/gpython_test.py

@@ -258,6 +258,7 @@ def test_pymain_opt():
 
     check([])
     check(["-O"])
+    if not (is_pypy and PY2): # https://foss.heptapod.net/pypy/pypy/-/issues/3356
         check(["-OO"])
         check(["-OOO"])
         check(["-O", "-O"])