"Routing Labels" is marked as Required(*) field on Create Receiver form, but user can still submit form creation without setting value to it    

4.21.0-0.nightly-2025-10-19-181151    

Always    

    1. goes to Create Receiver form /settings/cluster/alertmanagerconfig/receivers/~new
    2. choose any Receiver type and fill all required fields except "Routing labels" 
    3. submit the form

3. form can be successfully submitted    

3. If "Routing labels" is not required field, we should remove required field indicator * , otherwise we should prevent users from submitting form when it is missing