Bump pillow from 8.1.1 to 8.2.0 in /tests/tf-vision/model-server

Bumps [pillow](https://github.com/python-pillow/Pillow) from 8.1.1 to 8.2.0.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/master/CHANGES.rst)
- [Commits](python-pillow/Pillow@8.1.1...8.2.0)

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

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

tests/tf-vision/model-server/requirements.txt

@@ -1,3 +1,3 @@
 tensorflow_hub==0.6.0
 tensorflow==2.5.0
-Pillow==8.1.1
+Pillow==8.2.0