[FIX] base: show attachments of archives records

When testing the access rights, attachments associated with
archived/inactive records are inadvertently being hidden due to
the default ORM behavior of search.

Patch simplified while merging.

Closes #14366

odoo/addons/base/ir/ir_attachment.py

@@ -374,7 +374,7 @@ class IrAttachment(models.Model):
                 continue
             # filter ids according to what access rules permit
             target_ids = list(targets)
-            allowed = self.env[res_model].search([('id', 'in', target_ids)])
+            allowed = self.env[res_model].with_context(active_test=False).search([('id', 'in', target_ids)])
             for res_id in set(target_ids).difference(allowed.ids):
                 ids.difference_update(targets[res_id])