fix tests for Pytest-Asyncio running in strict mode

tests/test_web.py

@@ -4,13 +4,11 @@ import pytest
 from unwind import create_app
 from unwind import db, models, imdb
 
-# https://pypi.org/project/pytest-asyncio/
-pytestmark = pytest.mark.asyncio
-
 app = create_app()
 
 
-async def test_app(shared_conn):
+@pytest.mark.asyncio
+async def test_app(shared_conn: db.Database):
     async with shared_conn.transaction(force_rollback=True):
 
         # https://www.starlette.io/testclient/