fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-PILLOW-5918878

requirements.txt

@@ -17,4 +17,5 @@ sqlalchemy==1.4.23
 django-extensions==3.1.3
 setuptools==65.5.1 # not directly required, pinned by Snyk to avoid a vulnerability
 ipython>=8.10.0 # not directly required, pinned by Snyk to avoid a vulnerability
-numpy>=1.22.2 # not directly required, pinned by Snyk to avoid a vulnerability
+numpy>=1.22.2 # not directly required, pinned by Snyk to avoid a vulnerability
+pillow>=10.0.1 # not directly required, pinned by Snyk to avoid a vulnerability