Fix condition when no tables are present in Azure table parser

Author: DL

src/llmsearch/parsers/tables/azuredocint_parser.py

@@ -188,6 +188,9 @@ def __init__(self, fn: Path, cache_folder: Path):
     def detect_and_parse_tables(self) -> List[AzureParsedTable]:
         tables = self.table_pages_extractor.extract_table_pages()
 
+        if not tables:
+            return []
+
         with ThreadPoolExecutor(max_workers=min(10, len(tables))) as executor:
             future_to_fn = {
                 executor.submit(self._analyze_document, fn, page_mapping): (