fix(chatgpt): annotate the input coercion for the type-discipline gate

The LIT002 budget counts mutable-collection construction, and wrapping the
string input builds a list and a dict, which put the total two over its
ceiling. Both constructions are the wire payload this backend requires, so the
list cannot be replaced with an immutable equivalent; annotate the line with a
reason instead, matching the convention used elsewhere in the tree.

LIT005 freezes reasonless suppressions at zero, so the reason is required
rather than decorative.

Signed-off-by: Alexander Chernov <alexander@chernov.it>

litellm/llms/chatgpt/responses/transformation.py

@@ -69,7 +69,7 @@ class ChatGPTResponsesAPIConfig(OpenAIResponsesAPIConfig):
         # The Responses API accepts a string or a list, but this backend
         # rejects a string with {"detail": "Input must be a list"}.
         if isinstance(input, str):
-            input = [{"role": "user", "content": input}]
+            input = [{"role": "user", "content": input}]  # mutable-ok: the wire payload this backend requires
         request: Final = super().transform_responses_api_request(
             model,
             input,