refactor(rlsapi): drop redundant None assignments in response builders

- RlsapiV1InferData Optional fields already default to None via
  Field(None, ...), so explicit None assignments are unnecessary
- Applies to _build_infer_response non-verbose branch and
  _check_shield_moderation blocked response

Signed-off-by: Major Hayden <major@redhat.com>

Author: major

src/app/endpoints/rlsapi_v1.py

@@ -395,12 +395,6 @@ async def _check_shield_moderation(  # pylint: disable=too-many-arguments,too-ma
         data=RlsapiV1InferData(
             text=moderation_result.message,
             request_id=request_id,
-            tool_calls=None,
-            tool_results=None,
-            rag_chunks=None,
-            referenced_documents=None,
-            input_tokens=None,
-            output_tokens=None,
         )
     )
 
@@ -549,12 +543,6 @@ def _build_infer_response(
         data=RlsapiV1InferData(
             text=response_text,
             request_id=request_id,
-            tool_calls=None,
-            tool_results=None,
-            rag_chunks=None,
-            referenced_documents=None,
-            input_tokens=None,
-            output_tokens=None,
         )
     )