fix: typing (#2334)

## Issue Link / Problem Description
<!-- Link to related issue or describe the problem this PR solves -->
- Fixes typing

Author: anistark

src/ragas/backends/utils.py

@@ -1,17 +1,20 @@
 """Shared utilities for project module."""
 
+from __future__ import annotations
+
 import random
 import string
+import typing as t
 import uuid
 
 
-def create_nano_id(size=12):
+def create_nano_id(size: int = 12) -> str:
     """Create a short, URL-safe unique identifier."""
     # Define characters to use (alphanumeric)
     alphabet = string.ascii_letters + string.digits
 
     # Generate UUID and convert to int
-    uuid_int = uuid.uuid4().int
+    uuid_int = t.cast(int, uuid.uuid4().int)
 
     # Convert to base62
     result = ""

src/ragas/utils.py

@@ -621,13 +621,13 @@ def find_git_root(start_path: t.Union[str, Path, None] = None) -> Path:
     raise ValueError(f"No git repository found in or above {start_path}")
 
 
-def create_nano_id(size=12):
+def create_nano_id(size: int = 12) -> str:
     """Generate a short unique identifier."""
     # Define characters to use (alphanumeric)
     alphabet = string.ascii_letters + string.digits
 
     # Generate UUID and convert to int
-    uuid_int = uuid.uuid4().int
+    uuid_int = t.cast(int, uuid.uuid4().int)
 
     # Convert to base62
     result = ""