test_fractions: skip SIGSEG tests

Author: cosminbasca

graalpython/lib-python/3/test/test_fractions.py

@@ -615,6 +615,7 @@ def testApproximateCos1(self):
             s += num / fact * sign
         self.assertAlmostEqual(math.cos(1), s)
 
+    @unittest.skipIfGraalPython(reason="not yet supported, causes SEGFAULT")
     def test_copy_deepcopy_pickle(self):
         r = F(13, 7)
         dr = DummyFraction(13, 7)