fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-PILLOW-6219984
- https://snyk.io/vuln/SNYK-PYTHON-PILLOW-6219986

requirements.txt

@@ -25,3 +25,4 @@ tqdm
 numba==0.48
 #numba>=0.49.0 # not directly required, pinned by Snyk to avoid a vulnerability
 scikit-learn>=0.24.2 # not directly required, pinned by Snyk to avoid a vulnerability
+pillow>=10.2.0 # not directly required, pinned by Snyk to avoid a vulnerability