[#71305918] Remove `govuk::node::s_puppet` class
[#71305918] Remove `govuk::node::s_puppet` class

In [1881](https://github.gds/gds/puppet/pull/1881), it was noted that we
could remove this file as it's a class that has since been replaced
by `govuk::node::s_puppetmaster`. We no longer have `puppet-N` boxes since the move to Platform 1, therefore this class is entirely redundant.

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet