Remove enforcing of 10 items per list for declaration form macros
Remove enforcing of 10 items per list for declaration form macros

These macros are setting that the `items_per_list` for a list
macro will always have 10 items on it, overriding any behaviour
in the frameworks repo. If there is no specific value set
in the frameworks repo then this will default to 10 anyway.

Looking at g9 and DOS2 declarations, there were no declaration
questions which have custom `items_per_list` anyway so removing
this line wouldn't have made any difference to our previous
frameworks and therefore likely won't make any difference to future
frameworks either.

alphagov/digitalmarketplace-supplier-frontend,alphagov/digitalmarketplace-supplier-frontend,alphagov/digitalmarketplace-supplier-frontend,alphagov/digitalmarketplace-supplier-frontend