fix: tools/third_party/pytest-asyncio/dependencies/pytest-min/require…

…ments.txt to reduce vulnerabilities

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

tools/third_party/pytest-asyncio/dependencies/pytest-min/requirements.txt

@@ -2,3 +2,4 @@
 # when changing minimum version dependencies
 pytest == 6.1.0
 typing-extensions >= 3.7.2; python_version < "3.8"
+zipp>=3.19.1 # not directly required, pinned by Snyk to avoid a vulnerability