fix(VMenu): use last known position if target is hidden

[KaelWD]

Description

fixes #20515

Markup:

<template>
  <v-app>
    <v-container>
      <div style="height: 200px" />

      <div class="CONTAINER">
        <v-menu v-model="menu">
          <template #activator="{ props }">
            <v-btn class="BUTTON" color="primary" v-bind="props">
              Activator slot
            </v-btn>
          </template>
          <v-list>
            <v-list-item
              v-for="(item, index) in items"
              :key="index"
              :value="index"
            >
              <v-list-item-title>{{ item.title }}</v-list-item-title>
            </v-list-item>
          </v-list>
        </v-menu>
      </div>

      <div style="height: 2000px" />
    </v-container>
  </v-app>
</template>

<script setup>
  import { ref } from 'vue'
  const items = ref([
    { title: 'Click Me' },
    { title: 'Click Me' },
    { title: 'Click Me' },
    { title: 'Click Me 2' },
  ])
  const menu = ref(false)
</script>

<style>
.CONTAINER {
  display: flex;
  justify-content: center;
  padding: 16px;
  background-color: lightblue;
  height: 120px;
}

.BUTTON {
  display: none;
}

.CONTAINER:hover .BUTTON {
  display: block;
}
</style>