The previous image versions set ANSIBLE_WORKER_SESSION_ISOLATION=False in an
attempt to restore SSH prompts on Ansible 2.21. That setting does not bring
the prompts back — it makes Ansible hang silently at the first SSH connection
whenever a prompt would have been needed. See
https://github.com/devture/docker-ansible/issues/6

The new image auto-accepts the SSH host keys of previously unknown hosts
instead. The docs stop recommending ANSIBLE_WORKER_SESSION_ISOLATION=False
for direct (non-Docker) runs for the same reason, and now explain how to use
an ssh-agent for passphrase-protected SSH keys.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>