Fix download_artifact_job for  promote-openstack-manuals-developer
This was missed in a recent change, fix the name to match what is run.
See for a failure and job names.
- openstack/api-site
vars:
write_root_marker: false
- download_artifact_job: build-tox-manuals-checkbuild
+ download_artifact_job: build-tox-manuals-publishdocs
secrets:
- secret: afsdeveloper_secret-openstack-manuals
name: afs
