[FIX]l10n_be_intrastat_product_declaration - remove obsolete code

Remove check on VAT code on partner record.
This check has been moved to the intrastat_product module,
cf. OCA/intrastat-extrastat@17f5fcb

l10n_be_intrastat_product/models/intrastat_product_declaration.py

@@ -142,12 +142,6 @@ def _update_computation_line_vals(self, inv_line, line_vals, notedict):
                 self._handle_refund(inv_line, line_vals, notedict)
 
             if line_vals:
-                if self.declaration_type == "dispatches":
-                    if not line_vals.get("vat", ""):
-                        msg = _("Missing <em>VAT Number</em>")
-                        notedict["partner"][inv.partner_id.display_name][msg].add(
-                            notedict["inv_origin"]
-                        )
                 # extended declaration
                 if self.reporting_level == "extended":
                     incoterm = self._get_incoterm(inv_line, notedict)