Enable StrictHostKeyChecking for SSH connection to nodes

[abbashus]

On connecting to an address for which an SSH client has no known host key, it will prompt the user whether it wants to allow-list that key; subsequent connections to that address will fail if the server fails to present the same identity.

By setting StrictHostKeyChecking to no, the target code disables host key checking in the client. As a result, it will never check the identity of the server either on its first or subsequent connections. An attacker on the network will therefore be able to spoof a bastion or remote host (depending on network position) at any time (as opposed to just during the first connection) and a victim will have no way to detect this attack.