disabled not added to flux:select variant="listbox" on submit

[jeffchown]

When submitting a form, either a readonly or disabled attribute are added to controls (depending upon the control type).
This stops the user from being able to edit the form during submit and allows us to style the controls for visual feedback.

A flux:select variant="listbox" doesn't seem to receive any such attribute upon submit - which means I can't style it, and also it is still active/editable during submit.

If you use the code below and inspect the different controls in the browser's devtools, you'll see the attributes being added (or not, in the case of the listbox) during the sleep(3) I added to the save() method.

To reproduce, add the following to your app.css:

input:read-only,
textarea:read-only,
input:disabled,
textarea:disabled,
select:disabled { @apply !bg-gray-50 dark:!bg-white/[7%] hover:cursor-not-allowed; }

button:disabled, fieldset:disabled button { @apply hover:cursor-not-allowed; }

Then, this Volt component shows a listbox next to a few other controls:

<?php

use Livewire\Volt\Component;

new class extends Component {
    public function save()
    {
        sleep(3);
    }
}; 
?>

<div>
    <form wire:submit="save" class="space-y-2">
        <flux:input label="Flux:input" />

        <flux:select placeholder="Choose industry" label="Native select">
            <flux:option>Photography</flux:option>
            <flux:option>Design services</flux:option>
            <flux:option>Web development</flux:option>
            <flux:option>Accounting</flux:option>
            <flux:option>Legal services</flux:option>
            <flux:option>Consulting</flux:option>
            <flux:option>Other</flux:option>
        </flux:select>

        <flux:select variant="listbox" placeholder="Choose industry" label="Listbox variant">
            <flux:option>Photography</flux:option>
            <flux:option>Design services</flux:option>
            <flux:option>Web development</flux:option>
            <flux:option>Accounting</flux:option>
            <flux:option>Legal services</flux:option>
            <flux:option>Consulting</flux:option>
            <flux:option>Other</flux:option>
        </flux:select>

        <flux:select variant="combobox" placeholder="Choose industry" label="Combobox variant">
            <flux:option>Photography</flux:option>
            <flux:option>Design services</flux:option>
            <flux:option>Web development</flux:option>
            <flux:option>Accounting</flux:option>
            <flux:option>Legal services</flux:option>
            <flux:option>Consulting</flux:option>
            <flux:option>Other</flux:option>
        </flux:select>

        <flux:button type="submit">Save</flux:button>
    </form>
</div>