Bump pillow from 6.1.0 to 9.0.0

Bumps [pillow](https://github.com/python-pillow/Pillow) from 6.1.0 to 9.0.0.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst)
- [Commits](python-pillow/Pillow@6.1.0...9.0.0)

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

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements.txt

@@ -22,7 +22,7 @@ matplotlib==3.1.1
 networkx==2.3
 numpy==1.16.4
 opencv-python==3.3.0.9
-Pillow==6.1.0
+Pillow==9.0.0
 protobuf==3.9.0
 pyparsing==2.4.0
 python-dateutil==2.8.0