Issue: Keyboard navigation broken when using v-slot:beforeList

[LeGoffMael]

Thank you for building this great component !

Reproduction Link

vue 3.3.4, vue-multiselect 3.0.0

The v-slot:beforeList slot is actually not displayed in jsfiddle (no idea why), so it doesn't reproduce the error.
But the code to reproduce the error on local is the same
https://jsfiddle.net/mlegoff10/Lu4t9xzh/

In the following video v-slot:beforeList's height is fixed to 40px and :option-height is kept to default.

Screen.Recording.2024-07-16.at.6.21.52.PM.mov

Steps to reproduce

Add a v-slot:beforeList into the multiselect component.
When navigating through the options list using the keyboard the bottom is cut-out.

Expected behaviour

The library should take into account the v-slot:beforeList height (maybe by considering it to be equal to :option-height value)
The keyboard navigation should works properly even with a v-slot:beforeList.

Actual behaviour

The keyboard navigation does not work properly when using v-slot:beforeList.