Fix workflow samples

python/samples/03-workflows/orchestrations/handoff_simple.py

@@ -27,7 +27,7 @@ them to transfer control to each other based on the conversation context.
 
 Prerequisites:
     - FOUNDRY_PROJECT_ENDPOINT must be your Azure AI Foundry Agent Service (V2) project endpoint.
-    - Azure OpenAI configured for FoundryChatClient with required environment variables.
+    - FOUNDRY_MODEL must be set to your Azure OpenAI model deployment name.
     - Authentication via azure-identity. Use AzureCliCredential and run `az login` before executing the sample.
 
 Key Concepts:
@@ -201,7 +201,7 @@ async def main() -> None:
     # Initialize the Azure OpenAI Responses client
     client = FoundryChatClient(
         project_endpoint=os.environ["FOUNDRY_PROJECT_ENDPOINT"],
-        model=os.environ["AZURE_AI_MODEL_DEPLOYMENT_NAME"],
+        model=os.environ["FOUNDRY_MODEL"],
         credential=AzureCliCredential(),
     )