removed parallel worker subprocess fail screendump req'ment, so not to break the --parallel FT run

src/functional_tests/base.py

@@ -61,12 +61,15 @@ class FunctionalTest(StaticLiveServerTestCase):
         super().tearDown()
 
     def _test_has_failed(self):
+        try:
             return any(
                 failure[0] == self
                 for failure in itertools.chain(
                     self._outcome.result.failures, self._outcome.result.errors
                 )
             )
+        except TypeError:
+            return False
     
     def take_screenshot(self):
         path = SCREEN_DUMP_LOCATION / self._get_filename("png")
@@ -156,12 +159,15 @@ class ChannelsFunctionalTest(ChannelsLiveServerTestCase):
         super().tearDown()
 
     def _test_has_failed(self):
+        try:
             return any(
                 failure[0] == self
                 for failure in itertools.chain(
                     self._outcome.result.failures, self._outcome.result.errors
                 )
             )
+        except TypeError:
+            return False
 
     def take_screenshot(self):
         path = SCREEN_DUMP_LOCATION / self._get_filename("png")