[FIX] account: Don't generate pdf at all when trying to print a misc operation...

[FIX] account: Don't generate pdf at all when trying to print a misc operation from the 'print invoices' actions

Before, clicking on 'print invoices' or 'print invoices without payment' on a posted misc operation raised an error message saying that only invoices could be printed. However, the pdf file still got generated and could be found as attachement on the move. With this commit, we don't generate the file anymore in this case.

closes odoo/odoo#76419

Signed-off-by: Laurent Smet <smetl@users.noreply.github.com>