[FIX] l10n_it_edi: Relax zip check for non-Italian buyers.

With Italian localization, the length of zip must be 5 for Italian buyer.
If the buyer is not Italian, we doesn't check his zip length.

closes #31205

addons/l10n_it_edi/models/account_invoice.py

@@ -112,7 +112,7 @@ def _check_before_xml_exporting(self):
             raise UserError(_("%s must have a street.") % (buyer.display_name))
         if not buyer.zip:
             raise UserError(_("%s must have a post code.") % (buyer.display_name))
-        if len(buyer.zip) != 5:
+        if len(buyer.zip) != 5 and buyer.country_id.code == 'IT':
             raise UserError(_("%s must have a post code of length 5.") % (buyer.display_name))
         if not buyer.city:
             raise UserError(_("%s must have a city.") % (buyer.display_name))