fix(schema): add provider field to actor name test template for master compatibility

The merge with master introduced a new 'provider' field requirement for
LLM and GRAPH actors. Updated the step_given_actor_with_name test
template to include 'provider: openai' so server-qualified name
acceptance scenarios pass with the new validation rule.

ISSUES CLOSED: #9074

features/steps/actor_schema_steps.py

@@ -404,6 +404,7 @@ def step_given_actor_with_name(context: Context, name: str) -> None:
 name: {name}
 type: llm
 description: Test actor
+provider: openai
 model: gpt-4
 """