deps: Update dependency SQLAlchemy to v2.0.21 (#849)

Author: renovate-bot

requirements-test.txt

@@ -2,7 +2,7 @@ pytest==7.4.2
 mock==5.1.0
 pytest-cov==4.1.0
 pytest-asyncio==0.21.1
-SQLAlchemy==2.0.20
+SQLAlchemy==2.0.21
 sqlalchemy-pytds==1.0.0
 flake8==5.0.4
 flake8-annotations==2.9.1