Fix gitlab:geo:check_replication_verification_status spec

While writing !41618 (merged), the tests which I copied from check_replication_verification_status did not seem to act as expected. The output tests succeeded regardless of the output. I don't remember exactly if the exit code tests were affected.

But I discovered @brodock's abort_execution matcher which was perfect for this case anyway. So I suggest we go that route for this spec as well.