docs(tests): use get_results in Python parallel-workflow example

results.get_succeeded() is not a valid method on the Python BatchResult.
The handler raises AttributeError and the durable execution fails, so the
test asserting InvocationStatus.SUCCEEDED would fail.

Use results.get_results() to mirror the TypeScript fix in #196.

Author: yaythomas

examples/python/testing/examples/parallel-workflow.py

@@ -29,7 +29,7 @@ def handler(event, context: DurableContext) -> list:
         ],
         name="fetch-all",
     )
-    return results.get_succeeded()
+    return results.get_results()
 
 
 def test_executes_branches_in_parallel():