change: ssh host key verification prompts

[shreddedbacon]

General Checklist

• Affected Issues have been mentioned in the Closing issues section
• Documentation has been written/updated
• PR title is ready for inclusion in changelog

The go knownhosts implementation doesn't prompt for host keys if they're unknown.

The lagoon-cli ssh command previously just ignored host keys entirely. With the introduction of the logs support, this command checked host keys.

If a user had not previously connected to the ssh host before via ssh directly to accept the host key, then the command would return an error with knownhosts: key is unknown. With no way to proceed or accept the host key via lagoon-cli.

This implements similar logic that ssh uses with StrictHostKeyChecking, with accept-new and no.

• accept-new is the default, and will just accept the host key and add it to known hosts, it will still check if the host key has changed though and present an error if it detects this.
• no will just ignore the any host key checking

Users that use lagoon-cli in automation, if you encounter issues with the host key checks, you can add the flag --strict-host-key-checking no to ignore it, or set the the feature flag as below

lagoon config feature --strict-host-key-checking no
# to remove the feature set it to empty or 'accept-new'
lagoon config feature --strict-host-key-checking ""

or add the line stricthostkeychecking: no to your lagoon-cli config .lagoon.yml file.