refactor: remove optional return value

cognee/infrastructure/llm/structured_output_framework/litellm_instructor/llm/mistral/adapter.py

@@ -162,6 +162,5 @@ class MistralAdapter(GenericAPIAdapter):
                     "file_name": file_name,
                 },
             )
-            if transcription_response:
-                return TranscriptionReturnType(transcription_response.text, transcription_response)
-        return None
+
+            return TranscriptionReturnType(transcription_response.text, transcription_response)

cognee/infrastructure/llm/structured_output_framework/litellm_instructor/llm/openai/adapter.py

@@ -1,6 +1,6 @@
 import litellm
 import instructor
-from typing import Type, Optional
+from typing import Type
 from pydantic import BaseModel
 from openai import ContentFilterFinishReasonError
 from litellm.exceptions import ContentPolicyViolationError