fix(VSlider): fix thumb shifting position when toggling disabled state

[nekosaur]

Description

thumb got recreated when slider was disabled, instead of reused.

Motivation and Context

closes #11303

How Has This Been Tested?

playground

Markup:

<template>
  <div>
    <v-switch label="vertical" v-model="vertical"></v-switch>
    <v-switch label="rtl" v-model="$vuetify.rtl"></v-switch>
    <v-switch label="disabled ticks" v-model="enabledTicks"></v-switch>
    <v-slider max="10" min="0" ticks :disabled="!enabledTicks" v-model="slide" :vertical="vertical"></v-slider>
    <v-divider></v-divider>
    <v-switch label="disabled no ticks" v-model="enabledNoTicks"></v-switch>
    <v-slider max="10" min="0" :disabled="!enabledNoTicks" v-model="slide2"></v-slider>
  </div>
</template>

<script>
  export default {
    data: () => ({
      enabledNoTicks: true,
      enabledTicks: true,
      slide: 5,
      slide2: 5,
      vertical: false,
    }),
  }
</script>

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Improvement/refactoring (non-breaking change that doesn't add any features but makes things better)

Checklist:

• The PR title is no longer than 64 characters.
• The PR is submitted to the correct branch (master for bug fixes and documentation updates, dev for new features and backwards compatible changes and next for non-backwards compatible changes).
• My code follows the code style of this project.
• I've added relevant changes to the documentation (applies to new features and breaking changes in core library)