fix: align text color in dark mode for config var type selector (#25121)

web/app/components/app/configuration/config-var/config-modal/type-select.tsx

             <InputVarTypeIcon type={selectedItem?.value as InputVarType} className='size-4 shrink-0 text-text-secondary' />
             <span
               className={`
-              ml-1.5 ${!selectedItem?.name && 'text-components-input-text-placeholder'}
+              ml-1.5 text-components-input-text-filled ${!selectedItem?.name && 'text-components-input-text-placeholder'}
             `}
             >
               {selectedItem?.name}