fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-ZIPP-7430899

Author: snyk-bot

requirements.txt

@@ -23,4 +23,5 @@ appdirs
 tqdm
 funcy
 fsspec
-opencv-python
+opencv-python
+zipp>=3.19.1 # not directly required, pinned by Snyk to avoid a vulnerability