fix(VSlideGroup): skip disabled elements when moving focus

[babu-ch]

fix #20780

Description

Added recursively searching for non-disabled elements when retrieving siblingElement.

Markup:

<template>
  <v-sheet class="mx-auto" max-width="600">
    <v-slide-group show-arrows>
      <v-slide-group-item
        v-for="n in 10"
        :key="n"
        v-slot="{ isSelected, toggle }"
      >
        <v-btn
          :color="isSelected ? 'primary' : undefined"
          class="ma-2"
          rounded
          @click="toggle"
          :disabled="n%4 === 0"
        >
          Options {{ n }}
        </v-btn>
      </v-slide-group-item>
    </v-slide-group>
  </v-sheet>
</template>