
The known_host key is written out by the parent infra-prod-base job in
the run-production-playbook.yaml step [1]. We don't need to do this
here again.
[1] 2c194e5cbf/playbooks/zuul/run-production-playbook.yaml (L1)
Change-Id: I514132b2dbc20ac321a79ca2eb6d4c8b11c4296d