release: 3.19.1 (#3946)

Automated Release PR
---


##
[3.19.1](https://github.com/openai/openai-python/compare/v3.19.0...v3.19.1)
(2026-09-23)


### Bug Fixes

* **chat:** preserve single-pass tool iterables
([#3770](https://github.com/openai/openai-python/issues/3770))
([33ffa1f](https://github.com/openai/openai-python/commit/33ffa1f9fa4f49553ab0287b9359283be818fe40))
* **client:** merge HTTP headers case-insensitively
([#3486](https://github.com/openai/openai-python/issues/3486))
([5e39766](https://github.com/openai/openai-python/commit/5e39766dd7ba2802c97f5305721a621098cf0e38))


### Chores

* **api:** clarify Chat Completions seed limits
([#3945](https://github.com/openai/openai-python/issues/3945))
([be9d666](https://github.com/openai/openai-python/commit/be9d66628ad7377bd36fe5a76ae6d735843f0e76))


### Documentation

* clarify collaborator-only pull request policy
([#3948](https://github.com/openai/openai-python/issues/3948))
([ead1fa2](https://github.com/openai/openai-python/commit/ead1fa2473257ba5d7be08484aca4349649e6245))

---
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