Bump pillow from 5.4.1 to 9.0.0

Bumps [pillow](https://github.com/python-pillow/Pillow) from 5.4.1 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@5.4.1...9.0.0)

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

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

requirements.txt

@@ -16,7 +16,7 @@ Mako==1.0.7
 MarkupSafe==1.1.0
 nibabel==2.3.3
 numpy==1.16.0
-Pillow==5.4.1
+Pillow==9.0.0
 pyparsing==2.3.1
 python-dateutil==2.7.5
 python-dotenv==0.10.1