fix:'sqlalchemy' has no attribute '__all__'

backend_refactor/requirements.txt

@@ -5,7 +5,7 @@ numpy==1.21.6
 opencv-python==4.6.0.66
 matplotlib==3.5.3
 scipy==1.7.3
-flask_sqlalchemy==2.5.1
+flask_sqlalchemy==3.0.2
 mysqlclient==1.4.6
 flask-cors==3.0.10