fix: allow event managers to delete expired orders (#6178)

Author: abhinavk96

app/api/orders.py

@@ -282,7 +282,7 @@ def before_update_object(self, order, data, view_kwargs):
                 # Order created from the public pages.
                 for element in data:
                     if data[element] and data[element] != getattr(order, element, None):
-                        if element != 'status':
+                        if element != 'status' and element != 'deleted_at':
                             raise ForbiddenException({'pointer': 'data/{}'.format(element)},
                                                      "You cannot update {} of an order".format(element))
                         elif element == 'status' and order.amount and order.status == 'completed':