`ansible-vault` is the only cli command which knows how to handle the
rekey options `--new-vault-id` and `--new-vault-password-file`. No
point in exposing those rekey options to any of the other ansible
commands.
On a practical level I think this matters most in ensuring that
`--help` doesn't produce any false/unhelpful output.
(cherry picked from commit b78ab37a94)