chore(deps): bump pillow in /docs in the pip group across 1 directory

Bumps the pip group with 1 update in the /docs directory: [pillow](https://github.com/python-pillow/Pillow).


Updates `pillow` from 12.0.0 to 12.1.1
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst)
- [Commits](python-pillow/Pillow@12.0.0...12.1.1)

---
updated-dependencies:
- dependency-name: pillow
  dependency-version: 12.1.1
  dependency-type: indirect
  dependency-group: pip
...

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