remove job settings for nova repositories
remove job settings for nova repositories

This is a mechanically generated patch to remove the job settings that
have been migrated to the git repositories owned by the nova team.

See the python3-first goal document for details:
https://governance.openstack.org/tc/goals/stein/python3-first.html

Change-Id: I7be8d6a584ebe93e1a384d9f0672204f7affc221
Story: #2002586
Task: #24315

openstack-infra/project-config,openstack-infra/project-config