[3792792]x_studio_amount_to_invoice

#Done by RHT on the 07/03/2024
#Reviewed by EMI on the 03/04/2024
#Review: https://pastebin.com/L0MM1xBs
#911 task: https://www.odoo.com/web#id=3792792&cids=1&menu_id=4720&action=333&active_id=5686&model=project.task&view_type=form
#Need: to know the amount to invoice (non-recurrent)
for so in self:
    invoiced_amount = 0
    for invoice in so.invoice_ids:
        invoiced_amount += invoice.amount_untaxed
    diff =  so.non_recurring_total - invoiced_amount
    if diff > 0:
        so["x_studio_amount_to_invoice"] = diff
    else:
        so["x_studio_amount_to_invoice"] = 0