ed25519 upstream has new commits

[github-actions]

It seems https://github.com/pyca/ed25519.git has changed: Expected main to be commit 08a7962, found e5b868b instead (diff). Please review changes, update the vendored copy if needed, and then update the expected hash in _vendor/test-ed25519-upstream.sh

[jku]

there's nothing important in these changes but we should update the expected hash...