do_deactivate_stream: Remove unnecessary mutations.

Streams should not be marked as private, and subscribers
of the deactivated stream should not be removed.

Update the confirmation message when archiving a stream.

zerver/openapi/curl_param_value_generators.py

@@ -126,7 +126,7 @@ def add_emoji_to_message() -> dict[str, object]:
 
     # The message ID here is hardcoded based on the corresponding value
     # for the example message IDs we use in zulip.yaml.
-    message_id = 47
+    message_id = 48
     emoji_name = "octopus"
     emoji_code = "1f419"
     reaction_type = "unicode_emoji"