To help debug failing commands such as GIT CLONE github.com/user/privaterepo /code or FROM github.com/user/privaterepo+target it would be nice to have earthly --verbose display the contents of all the known_hosts which are sent over to buildkit (as well as a total count of entries -- to make it easy for cases where there's 0 entries).

The context surrounding this issue is that a user was having buildkit fail with a ssh unknown fingerprint type of error, and it was not clear why, because the user had entries in their host's known_hosts file. Earthly should be sending this over with the llb request, so it would be nice to display those entries under the --verbose mode.