Simplify error handling in parallel_testsuite (#25766)

The `test(result)` call already contains a try/catch for landing errors
and skipping internally so the extra exception blocks here were not
doing anything.

What is more, if they ever did execute they would fail because the
second argument to `addError` and `addSkip` is not an exception object
but and exception info triple.

Author: sbc100

test/parallel_testsuite.py

@@ -51,33 +51,27 @@ def run_test(args):
   if allowed_failures_counter and allowed_failures_counter.value < 0:
     return None
 
-  def test_failed():
-    if allowed_failures_counter is not None:
-      with lock:
-        allowed_failures_counter.value -= 1
+  # Handle setUpClass which needs to be called on each worker
+  # TODO: Better handling of exceptions that happen during setUpClass
+  if test.__class__ not in seen_class:
+    seen_class.add(test.__class__)
+    test.__class__.setUpClass()
 
   start_time = time.perf_counter()
-
   olddir = os.getcwd()
   result = BufferedParallelTestResult()
   result.start_time = start_time
   result.buffer = buffer
   temp_dir = tempfile.mkdtemp(prefix='emtest_')
   test.set_temp_dir(temp_dir)
   try:
-    if test.__class__ not in seen_class:
-      seen_class.add(test.__class__)
-      test.__class__.setUpClass()
     test(result)
 
     # Alert all other multiprocess pool runners that they need to stop executing further tests.
     if result.test_result not in ['success', 'skipped']:
-      test_failed()
-  except unittest.SkipTest as e:
-    result.addSkip(test, e)
-  except Exception as e:
-    result.addError(test, e)
-    test_failed()
+      if allowed_failures_counter is not None:
+        with lock:
+          allowed_failures_counter.value -= 1
   finally:
     result.elapsed = time.perf_counter() - start_time