Fix typing issues for mypy (#372)

src/khoj/processor/conversation/gpt4all/chat_model.py

@@ -21,7 +21,7 @@ def extract_questions_offline(
     conversation_log={},
     use_history: bool = True,
     should_extract_questions: bool = True,
-):
+) -> List[str]:
     """
     Infer search queries to retrieve relevant notes to answer user query
     """

src/khoj/routers/api.py

@@ -703,8 +703,8 @@ async def extract_references_and_questions(
 
     # Initialize Variables
     conversation_type = "general" if q.startswith("@general") else "notes"
-    compiled_references = List[Any]
-    inferred_queries = List[Any]
+    compiled_references: List[Any] = []
+    inferred_queries: List[str] = []
 
     if state.content_index is None:
         logger.warn(