release: Complete NO_ROOTification of Vagrant builds

[markj]

Summary

• Don't clean pkg files, they won't be recorded in the manifest anyway.
• Use pw's new metalog mode to create the vagrant user. Note that we do not need to manually create the home directory, pw will do it, so just remove that.
• Write metalog entries for the vagrant user's ssh key dir and authorized keys file

Note, this depends on an updated pw being installed on the host.

[emaste]

release/tools/vagrant.conf

17–26

Can we just remove the test, always using this path?

[markj]

Remove some unintended modifications.

[markj]

release/tools/vagrant.conf

17–26

Not quite:

• Below we're invoking pkg -c, which causes pkg to chroot itself.
• rm -r will fail if the target doesn't exist.

I don't have a good way to test these images at the moment so didn't want to change it more than necessary.

At some point this block should be deduplicated, it's copied across most of the cloudware configurations.

[emaste]

Looks fine to me; there are outstanding issues with the VAGRANT images anyhow so it's good to get this in and we can continue to iterate on existing problems.