fix(VCarouselItem): fix class props

[SonTT19]

Description

fixes #19630

Markup:

<template>
  <v-app>
    <v-container>
      <v-carousel>
        <v-carousel-item
          class="docks"
          src="https://cdn.vuetifyjs.com/images/cards/docks.jpg"
          cover
        ></v-carousel-item>

        <v-carousel-item
          class="hotel"
          src="https://cdn.vuetifyjs.com/images/cards/hotel.jpg"
          cover
        ></v-carousel-item>

        <v-carousel-item
          class="sunshine"
          src="https://cdn.vuetifyjs.com/images/cards/sunshine.jpg"
          cover
        ></v-carousel-item>
      </v-carousel>
    </v-container>
  </v-app>
</template>