fix: llamaIndex latest version (#604)

Author: jjmachan

src/ragas/testset/generator.py

@@ -32,7 +32,7 @@
 
 if t.TYPE_CHECKING:
     from langchain_core.documents import Document as LCDocument
-    from llama_index.readers.schema import Document as LlamaindexDocument
+    from llama_index.core.schema import Document as LlamaindexDocument
 
 logger = logging.getLogger(__name__)