chore(deps): bump pillow from 8.3.2 to 9.0.1 in /requirements

Bumps [pillow](https://github.com/python-pillow/Pillow) from 8.3.2 to 9.0.1.
- [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...9.0.1)

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

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

Author: dependabot[bot]

requirements/base.txt

@@ -18,7 +18,7 @@ Markdown==3.2.1
 reportlab==3.5.55
 requests
 requests_oauthlib
-Pillow==8.3.2
+Pillow==9.0.1
 premailer
 populus
 psycopg2-binary==2.8