Try to fix mypy Base class error

Author: jonathanl-bq

tests/integration/container/sqlalchemy/test_sqlalchemy_basic.py

@@ -40,7 +40,10 @@
 from ..utils.test_environment import TestEnvironment
 from ..utils.test_environment_features import TestEnvironmentFeatures
 
-Base = declarative_base()
+class Base:
+    __allow_unmapped__ = True
+
+Base = declarative_base(cls=Base)
 
 class TestModel(Base):
     """Basic test model for SQLAlchemy ORM functionality"""
@@ -688,15 +691,15 @@ def test_sqlalchemy_load_only_and_defer(self, test_environment: TestEnvironment,
         session.expire_all()
         # Test load_only() - load only specific fields
         obj_only = session.query(TestModel).options(
-            load_only('TestModel.name', 'TestModel.email')
+            load_only(TestModel.name, TestModel.email)
         ).get(obj_id)
         assert obj_only.name == "Test User"
         assert obj_only.email == "test@example.com"
         assert obj_only.age == 30
         session.expire_all()
         # Test defer() - exclude specific fields from loading
         obj_defer = session.query(TestModel).options(
-            defer('TestModel.age'), defer('TestModel.is_active')
+            defer(TestModel.age), defer(TestModel.is_active)
         ).get(obj_id)
         assert obj_defer.name == "Test User"
         assert obj_defer.email == "test@example.com"