[Openstack-stable-maint] Stable check of openstack/oslo.serialization for ref refs/heads/stable/xena failed

Build failed. https://zuul.opendev.org/t/openstack/buildset/1aff9e5990ab41a4b473b0f471ef87... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/e1e11d491aec4a71a61a2c41254b371e : TIMED_OUT in 30m 53s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/46503a710a3841c0b4784f7999ef2a88 : SUCCESS in 2m 28s - openstack-tox-py38 https://zuul.opendev.org/t/openstack/build/998a090c772f43c2b7d5b8e8813b038d : TIMED_OUT in 40m 35s