Bump websockets from 8.1 to 9.1 in /python/api

Bumps [websockets](https://github.com/aaugustin/websockets) from 8.1 to 9.1.
- [Release notes](https://github.com/aaugustin/websockets/releases)
- [Changelog](https://github.com/aaugustin/websockets/blob/9.1/docs/changelog.rst)
- [Commits](python-websockets/websockets@8.1...9.1)

---
updated-dependencies:
- dependency-name: websockets
  dependency-type: direct:production
...

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