The "python-path" configuration option makes its way through to Zuul
where it sets the "ansible_interpreter_path" in the inventory.
Currently this defaults to "/usr/bin/python2" which is wrong for
Python 3-only distributions.
Ansible >=2.8 provides for automated discovery of the interpreter to
avoid runtime errors choosing an invalid interpreter [1]. Using this
should mean that "python-path" doesn't need to be explicitly for any
common case. As more distributions become Python 3 only, this should
"do the right thing" without further configuration.
This switches the default python-path to "auto". The dependent change
updates Zuul to accept this and use it when running with Ansible
>=2.8, or default back to "/usr/bin/python2" for earlier Ansible
versions.
Testing and documentation is updated, and a release note added.
[1] https://docs.ansible.com/ansible/2.8/reference_appendices/interpreter_discovery.html
Depends-On: https://review.opendev.org/682275
Change-Id: I02a1a618c8806b150049e91b644ec3c0cb826ba4
db87a0845f