fix(VBtnToggle): buttons should be accessible despite overflow

[jcjp]

Description

• Fixes: https://github.com/vuetifyjs/vuetify/issues/15398

Markup:

<template>
  <v-app>
    <v-container>
      <v-btn-toggle v-model="msg">
        <v-btn v-for="n in 6" :key="n" :value="n">{{ n }}</v-btn>
      </v-btn-toggle>
      <v-text-field v-model="msg" />
    </v-container>
  </v-app>
</template>

<script setup>
  import { ref } from 'vue'

  const msg = ref(0)

  const callNext = () => {
    msg.value++
  }
</script>