skip test_send_periodic_duration() in CI

Author: zariiii9003

test/back2back_test.py

@@ -273,7 +273,7 @@ def test_sub_second_timestamp_resolution(self):
         self.bus2.recv(0)
         self.bus2.recv(0)
 
-    @unittest.skipIf(IS_PYPY, "fails randomly when run on CI server")
+    @unittest.skipIf(IS_CI, "fails randomly when run on CI server")
     def test_send_periodic_duration(self):
         """
         Verify that send_periodic only transmits for the specified duration.