docs: Make delete-stream use curl example system.

templates/zerver/api/delete-stream.md

@@ -13,10 +13,7 @@
 
 {tab|curl}
 
-``` curl
-curl -X DELETE {{ api_url }}/v1/streams/{stream_id} \
-    -u BOT_EMAIL_ADDRESS:BOT_API_KEY
-```
+{generate_code_example(curl)|/streams/{stream_id}:delete|example}
 
 {end_tabs}
 

zerver/openapi/test_curl_examples.py

@@ -22,6 +22,7 @@ exclude_list = [
     'update-subscription-properties.md',
     'remove-subscriptions.md',
     'get-stream-topics.md',
+    'delete-stream.md',
 ]
 
 def test_generated_curl_examples_for_success(client: Client) -> None: