fix: use typing_extensions.TypedDict for Python <3.12 compat

Also fix black formatting in test file.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: AdirAmsalem

decart/tokens/types.py

@@ -1,4 +1,4 @@
-from typing import TypedDict
+from typing_extensions import TypedDict
 
 from pydantic import BaseModel
 

tests/test_tokens.py

@@ -185,9 +185,7 @@ async def test_create_token_with_constraints() -> None:
         await client.tokens.create(constraints=constraints)
 
     call_kwargs = mock_session.post.call_args
-    assert call_kwargs.kwargs["json"] == {
-        "constraints": {"realtime": {"maxSessionDuration": 120}}
-    }
+    assert call_kwargs.kwargs["json"] == {"constraints": {"realtime": {"maxSessionDuration": 120}}}
 
 
 @pytest.mark.asyncio