Skip danger roulette message when there's no need
Problem to solve
Currently, danger roulette adds a message like !18669 (comment 231285694) which makes it slightly useless since that merge request would be automatically merged when the pipeline would pass.
Intended users
Proposal
Let's skip danger roulette message when automatic merge has been enabled.
Additionally, danger roulette could skip adding the message when the assignee list is not empty.