docs: Make delete-message use curl example system.

templates/zerver/api/delete-message.md

@@ -19,10 +19,7 @@ the Zulip Help Center.
 
 {tab|curl}
 
-``` curl
-curl -X DELETE {{ api_url }}/v1/messages/{message_id} \
-    -u BOT_EMAIL_ADDRESS:BOT_API_KEY \
-```
+{generate_code_example(curl)|/messages/{message_id}:delete|example}
 
 {end_tabs}
 

zerver/openapi/test_curl_examples.py

@@ -22,6 +22,7 @@ exclude_list = [
     # state of the DB. This results in the curl request to fail.
     'get-raw-message.md',
     'update-message.md',
+    'delete-message.md',
 ]
 
 def test_generated_curl_examples_for_success(client: Client) -> None: