Merge pull request #663 from bashtage/snyk-fix-dc3b25676fa44fefb139b3775d687b0b

[Snyk] Security upgrade zipp from 3.15.0 to 3.19.1

Author: bashtage

requirements-dev.txt

@@ -24,4 +24,5 @@ sphinx-immaterial
 sphinxcontrib-spelling
 sphinx_autodoc_typehints
 wheel
-flake8-bugbear
+flake8-bugbear
+zipp>=3.19.1 # not directly required, pinned by Snyk to avoid a vulnerability