fix: add return_dict=True to fix TypeError in prompt_chaining tests

The workflow.start() method returns a string by default (for backward compatibility),
but the test files were expecting a dictionary. Fixed by adding return_dict=True
parameter to get the expected dictionary format with task_results and task_status keys.

Fixes #841

Co-authored-by: Mervin Praison <[email protected]>

Author: claude[bot]

examples/python/general/prompt_chaining.py

@@ -72,7 +72,7 @@ def get_time_check():
 )
 
 # Run the workflow
-results = workflow.start()
+results = workflow.start(return_dict=True)
 
 # Print results
 print("\nWorkflow Results:")

src/praisonai-agents/tests/prompt_chaining.py

@@ -69,7 +69,7 @@ def get_time_check():
 )
 
 # Run the workflow
-results = workflow.start()
+results = workflow.start(return_dict=True)
 
 # Print results
 print("\nWorkflow Results:")