Make `close()` permissionless

[sembrestels]

From Sohkai's review: Does close() need to be guarded by a role? Wouldn't it be better if anyone could call it? Worried that the account who needs to call close() never does.

Note: close() is being used by a separate app, to finalize the initial fundraise. Consider changing the functionality in the separate app to read from a closed Hatch than requiring only that app to call close().

[sembrestels]

Changing this implies changes in the Impact Hours, Hatch Template, and many documentation. We leave it for the future.