refactor(FE-Storyless): conditionally handle onChange prop in SelectInput for better flexibility

src/components/input/SelectInput.tsx

@@ -146,7 +146,7 @@ const SelectInput = <T extends OptionType>(props: SelectInputProps<T>) => {
       <SelectComponent<T, boolean, GroupBase<T>>
         instanceId='select'
         value={value ?? (isMulti ? [] : null)}
-        onChange={handleChange}
+        onChange={onChange ? handleChange : undefined}
         options={options}
         menuIsOpen={openMenu}
         inputValue={internalInputValue}