fix(VMenu): keep open when selecting and open-delay="0"

[J-Sek]

• forces minimal 1ms delay for blur and focusout

fixes #21591

Markup:

<template>
  <v-app theme="dark">
    <v-container>
      <v-alert class="mb-4">
        Note: focus with <v-kbd>TAB</v-kbd> then use arrows
        <v-kbd>↑</v-kbd>/<v-kbd>↓</v-kbd> to select an item
      </v-alert>
      <v-menu
        close-delay="0"
        open-delay="0"
        transition="slide-x-transition"
        open-on-hover
      >
        <template #activator="{ props }">
          <v-btn v-bind="props">Test</v-btn>
        </template>
        <v-list :items="items" />
      </v-menu>
    </v-container>
  </v-app>
</template>

<script setup>
  const items = ['Item 1', 'Item 2', 'Item 3']
</script>