[FIX] purchase_request: Prevent unlink of protected mail activity data.

Author: bizzappdev

purchase_request/tests/test_purchase_request_procurement.py

@@ -104,7 +104,6 @@ def test_procure_purchase_request(self):
         self.env["mail.activity"].search(
             [("activity_type_id", "=", activity.id)]
         ).unlink()
-        activity.unlink()
         self.assertFalse(move.created_purchase_request_line_id.request_id.activity_ids)
         move._action_cancel()
         self.assertTrue(move.created_purchase_request_line_id.request_id.activity_ids)