Voiding and deleting invoices follows your role settings

Who can void or delete an invoice is now decided by the "Create and change invoices" permission in Settings → Team → Roles & Permissions. Nothing changes for your team unless you change that switch.

Turned off for a role — that role no longer sees Void or Delete on an invoice, and can't remove one any other way.
Turned on for Staff — Staff can now void and delete invoices too. Until now the switch made no difference here.
Owners and admins — can always void and delete, as before. The rules about which invoices can be removed are unchanged: paid invoices still need a credit note.