The version option and the release option are no longer needed since
openstackdocstheme 1.20.0 . These lines were already removed from
ironic by [1].
[1] https://review.opendev.org/c/openstack/ironic/+/663474
Change-Id: Ifdb7b6e2a3a99e121f57c1fd5811422f672d4870