tooz 8.1.0 release

meta:version: 8.1.0
meta:team: oslo
meta:diff-start: -
meta:series: independent
meta:branch: master
meta:release-type: release
meta:pypi: yes
meta:first: no
meta:release:Author: Takashi Kajinami <kajinamit@oss.nttdata.com>
meta:release:Commit: Takashi Kajinami <kajinamit@oss.nttdata.com>
meta:release:Change-Id: I4f11ada8b0680d54f725c3398b345b910cebe431
meta:release:Code-Review+2: Elod Illes <elod.illes@est.tech>
meta:release:Workflow+1: Elod Illes <elod.illes@est.tech>