build(deps): bump pillow from 8.3.2 to 9.0.0 in /requirements

Bumps [pillow](https://github.com/python-pillow/Pillow) from 8.3.2 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@8.3.2...9.0.0)

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

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

requirements/requirements-ci.txt

@@ -469,7 +469,7 @@ pickleshare==0.7.5
     # via
     #   -r requirements-dev.txt
     #   ipython
-pillow==8.3.2
+pillow==9.0.0
     # via
     #   -r requirements-dev.txt
     #   matrix-synapse

requirements/requirements-dev.txt

@@ -416,7 +416,7 @@ phonenumbers==8.10.13
     # via matrix-synapse
 pickleshare==0.7.5
     # via ipython
-pillow==8.3.2
+pillow==9.0.0
     # via matrix-synapse
 pip-tools==6.4.0
     # via -r requirements-dev.in