Fix: Duplicated Items in auto_paging_iter in stripe-python

### Describe the bug This is a strange bug, as it happens randomly. I do have to run the same test multiple times, and it happens maybe on 40%-60% of the instances. The issue I'm facing is that `auto_paging_iter` is iterating, and consequently returning, the same item twice. I'm trying to call `search_prices` API, and I do have 15 prices to be returned. I'm filtering `active=true` and some metadata fields. Then, I do the following: ```python prices: List[Price] = [] res = client.prices.search(params={"query": query_str}) print(res) for price in res.auto_paging_iter(): print(f"Real adding {price.id}") prices.append(price) ``` In the first response, I see `price_1SH9GKCjrU80UaAVjS6Nm5aL` being returned as the last entry. Then, in the logs, I see this: ``` Real adding ... Real adding price_1SH9GKCjrU80UaAVjS6Nm5aL Real adding price_1SH9GKCjrU80UaAVjS6Nm5aL Real adding ... ``` Could it be possible that the auto paging iterator is not properly respecting the `next_page` key, and is "repeatedly returning" the same item twice? ### To Reproduce 1. Call Prices Search API with `auto_paging_iterator`, with `active=true` and some metadata fields. 2. Make sure there are over 10 prices matching, to force pagination. 3. Log the unique IDs. At position 10 (default page size), it may sometimes be duplicated. ### Expected behavior `auto_paging_iter` should not iterate over duplicated prices ### Code snippets ```Python See above ``` ### OS Linux ### Language version Python 3.13 ### Library version stripe 12.3.0 ### API version 2025-03-31.basil ### Additional context _No response_