fix: use Python 3.9 compatible builtin generics

- Convert List[str] to list[str], Dict[str, Any] to dict[str, Any], etc.
- Use ruff --unsafe-fixes to automatically apply all type annotation updates
- Remove deprecated typing imports (List, Dict, Tuple) where no longer needed
- Keep Optional[str] syntax (union operator | not supported in Python 3.9)

Now all type annotations are Python 3.9 compatible with modern builtin generics.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

packages/leann-backend-diskann/leann_backend_diskann/graph_partition_simple.py

@@ -15,7 +15,7 @@ from typing import Optional
 
 def partition_graph_simple(
     index_prefix_path: str, output_dir: Optional[str] = None, **kwargs
-) -> Tuple[str, str]:
+) -> tuple[str, str]:
     """
     Simple function to partition a graph index.