[#51241141] Embargoed herder_timeout for Whitehall
[#51241141] Embargoed herder_timeout for Whitehall

This requires a new release of unicornherder to support the `-t` argument.
Whitehall will fail to start until unicornherder is upgraded. So temporarily
disable it for the moment.

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