Bump pillow from 8.1.0 to 8.3.2

Bumps [pillow](https://github.com/python-pillow/Pillow) from 8.1.0 to 8.3.2.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/master/CHANGES.rst)
- [Commits](python-pillow/Pillow@8.1.0...8.3.2)

---
updated-dependencies:
- dependency-name: pillow
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>