Update more tests not to use Python 3.8 (#13755)
## Summary
Update a few more tests to avoid using Python 3.8 unnecessarily. From
what I can see, neither of these really need that specific Python
version, so just update them to use 3.9 instead.
Bug #13676
## Test Plan
Uninstall Python 3.8 and run: `cargo test --no-default-features
--features git,pypi,python`
One test failure remains.
