fix(VTreeview): allow expanding disabled nodes

[oumoussa98]

fixes #21075

Description

Markup:

<template>
  <v-app>
    <v-container>
      <v-treeview :items="items" selectable />
    </v-container>
  </v-app>
</template>

<script setup>
import { ref } from "vue";

const items = [
  {
    id: 1,
    title: "Files :",
    props: { disabled: false },
    children: [
      { id: 2, title: "Calendar : app" },
      { id: 3, title: "Chrome : app", props: { disabled: true } },
      { id: 4, title: "Webstorm : app" },
    ],
  },
  {
    id: 5,
    title: "Applications :",
    props: { disabled: true },
    children: [
      { id: 6, title: "Calendar : app" },
      { id: 7, title: "Chrome : app", props: { disabled: true } },
      { id: 8, title: "Webstorm : app" },
    ],
  },
];
</script>