Should we drop support for New Dynamics?

[hdyson]

✨ Feature Request

New Dynamics has not been supported by the model for many years, and the team have limited experience of New Dynamics. Should we formalise that ANTS no longer supports New Dynamics?

Requirements

This would imply updating documentation, and dropping the --grid-staggering argument for ancil_2anc.

Context

This cannot be in the 3.0 release - we should have at least one GitHub release that retains New Dynamics support.

[hdyson]

From old trac ticket, here's a bit of context for the New Dynamics and ENDGame grids that we may want to refer to in future: