required attribute dont work when isSearchable={false}

Hi, I was developing a form using your Select component and I want to make it required using like https://github.com/rob-balfre/svelte-select/issues/214#issuecomment-746589030:

inputAttributes={ { required: !selectedRole } }

But I have found with to issues related to this. First of all, required is not working fine. If true, select doesn't check if value are set or not. I cannot submit form because always throw "Mandatory field". This is the reason why I use the negation of the value to control the required and set it to False when value is set.

The second problem is about "isSearchable" exported property. If I set it to false, because I don't want that the user use it to filter, required doesn't work. I mean, the previous solution found (or the usual required use) not work because select never detect that the component is required, so if required is true and Select is not searchable, I could submit the form without set any value on it.

Thanks!

rob-balfre / svelte-select

required attribute dont work when isSearchable={false} #438