fix: LegacyAPIWarning

* LegacyAPIWarning: The Query.get() method is considered legacy as of
  the 1.x series of SQLAlchemy and becomes a legacy construct in 2.0.
  The method is now available as Session.get() (deprecated since:
  2.0) (Background on SQLAlchemy 2.0 at: https://sqlalche.me/e/b8d9)
    return self.user_model.query.get(identifier)

flask_security/datastore.py

@@ -190,7 +190,7 @@ def get_user(self, identifier):
         from sqlalchemy import func as alchemyFn
 
         if self._is_numeric(identifier):
-            return self.user_model.query.get(identifier)
+            return self.db.session.get(self.user_model, identifier)
         for attr in get_identity_attributes():
             query = alchemyFn.lower(getattr(self.user_model, attr)) == alchemyFn.lower(
                 identifier