Do not copy project works nor progresses when copying invoice line

Closes #13369
(grafted from 1c267cd4cc2a87f17c6b2f2934a1fd81d8674b36)

--HG--
branch : 6.0

modules/project_invoice/invoice.py

@@ -8,6 +8,13 @@ from trytond.tools import grouped_slice
 class InvoiceLine(metaclass=PoolMeta):
     __name__ = 'account.invoice.line'
 
+    @classmethod
+    def copy(cls, lines, default=None):
+        default = default.copy() if default is not None else {}
+        default.setdefault('project_invoice_works')
+        default.setdefault('project_invoice_progresses')
+        return super().copy(lines, default=default)
+
     @classmethod
     def delete(cls, lines):
         pool = Pool()