[Openstack-stable-maint] Stable check of openstack/tooz for ref refs/heads/stable/train failed

Build failed. https://zuul.opendev.org/t/openstack/buildset/d034eef77a9b406c9b2892241a24b9... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/4739685643bd4c2998a21333d7257235 : FAILURE in 4m 36s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/6ad090556ef941fc91cdbe092b4cc2c6 : FAILURE in 3m 37s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/2fbb8805d7bc4634b7c67f5aa70978a3 : FAILURE in 3m 56s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/f50cea3ca2174858a7f7740395b7d0c0 : FAILURE in 4m 29s