Fix allow_mail_archived_partner causing system notifications to send emails

archived_partner_show_warning/models/sale_order.py

@@ -0,0 +1,15 @@
+from odoo import models, fields, api
+
+class SaleOrder(models.Model):
+    _inherit = 'sale.order'
+    
+    partner_is_archived = fields.Boolean(
+        string='Partner Archived',
+        compute='_compute_partner_is_archived',
+        store=False
+    )
+    
+    @api.depends('partner_id', 'partner_id.active')
+    def _compute_partner_is_archived(self):
+        for order in self:
+            order.partner_is_archived = order.partner_id and not order.partner_id.active