Bump pillow from 9.0.0 to 9.3.0 in /api

Bumps [pillow](https://github.com/python-pillow/Pillow) from 9.0.0 to 9.3.0.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst)
- [Commits](python-pillow/Pillow@9.0.0...9.3.0)

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

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

Author: dependabot[bot]

api/requirements.txt

@@ -3,5 +3,5 @@ Werkzeug==1.0.1
 requests==2.24.0
 python-dotenv==0.14.0
 firebase-admin==4.3.0
-Pillow==9.0.0
+Pillow==9.3.0
 colorgram.py==1.2.0