various mypy improvements

backend/onyx/connectors/airtable/airtable_connector.py

@@ -369,11 +369,12 @@ class AirtableConnector(LoadConnector):
         # Process records in parallel batches using ThreadPoolExecutor
         PARALLEL_BATCH_SIZE = 8
         max_workers = min(PARALLEL_BATCH_SIZE, len(records))
+        record_documents: list[Document] = []
 
         # Process records in batches
         for i in range(0, len(records), PARALLEL_BATCH_SIZE):
             batch_records = records[i : i + PARALLEL_BATCH_SIZE]
-            record_documents: list[Document] = []
+            record_documents = []
 
             with ThreadPoolExecutor(max_workers=max_workers) as executor:
                 # Submit batch tasks

backend/onyx/connectors/salesforce/doc_conversion.py

@@ -59,6 +59,7 @@ def _clean_salesforce_dict(data: dict | list) -> dict | list:
     elif isinstance(data, list):
         filtered_list = []
         for item in data:
+            filtered_item: dict | list
             if isinstance(item, (dict, list)):
                 filtered_item = _clean_salesforce_dict(item)
                 # Only add non-empty dictionaries or lists