`pn.widgets.Select`: `disabled_options` not working with `groups`

[ambrustorok]

Have a Select widget defined with groups and some of the options disabled. The disabled options can still be selected from the dropdown.

Define your widget, then select an option marked as disabled:

import panel as pn
pn.extension()

select = pn.widgets.Select(name="Select", groups={'Group 1:': ['Methane', 'Ethane', 'Propane'], 'Group 2': ['Butane', 'Pentane', 'Hexane']}, disabled_options=['Pentane', 'Hexane'])
select

The following code will print 'Pentane' even though it was disabled.

select.value