Update SQLAlchemy, Flask, Flask-SQLAlchemy, and other packages to current versions. #5901

Remove the python version check from the requirements.txt.

web/pgadmin/browser/server_groups/servers/tests/test_check_ssh_mock_connect.py

@@ -7,13 +7,12 @@
 #
 ##########################################################################
 
-from config import PG_DEFAULT_DRIVER
 from pgadmin.utils.route import BaseTestGenerator
 from regression.python_test_utils import test_utils as utils
 from . import utils as servers_utils
 from unittest.mock import patch, MagicMock
 import json
-from PG_DEFAULT_DRIVER import OperationalError
+from psycopg import OperationalError
 
 
 class ServersSSHConnectTestCase(BaseTestGenerator):

web/pgadmin/browser/utils.py

@@ -13,7 +13,7 @@ from abc import abstractmethod
 
 import flask
 from flask import render_template, current_app
-from flask.views import View, MethodViewType
+from flask.views import View, MethodView
 from flask_babel import gettext
 
 from config import PG_DEFAULT_DRIVER
@@ -140,7 +140,7 @@ class PGChildModule():
         pass
 
 
-class NodeView(View, metaclass=MethodViewType):
+class NodeView(View, metaclass=type(MethodView)):
     """
     A PostgreSQL Object has so many operaions/functions apart from CRUD
     (Create, Read, Update, Delete):