users: Add new user 'shiva' as realm moderator.

Note that at this point, it's not possible to create moderator users;
this just will make it easier to write tests for logic involving them
as we develop the feature.

zerver/openapi/python_examples.py

@@ -84,7 +84,7 @@ def add_subscriptions(client: Client) -> None:
     # {code_example|start}
     # To subscribe other users to a stream, you may pass
     # the `principals` argument, like so:
-    user_id = 25
+    user_id = 26
     result = client.add_subscriptions(
         streams=[
             {"name": "new stream", "description": "New stream for testing"},