[FIX] hr_payroll: Compute all payslips when closing batch

Closing a Payslip Batch has to ensure that all payslips inside of it
are well calculated and closed. Otherwise some helpers (as `sum`) won't
work correctly because there are open payslips from the last month batch.

This action ensures that if there's a Payslip Batch with 200+ employees,
closing the Batch will complete the whole process including the accounting.

closes odoo/odoo#25755

addons/hr_payroll/models/hr_payslip.py

@@ -506,4 +506,5 @@ class HrPayslipRun(models.Model):
 
     @api.multi
     def close_payslip_run(self):
+        self.mapped('slip_ids').filtered(lambda payslip: payslip.state != 'done').action_payslip_done()
         return self.write({'state': 'close'})