fix(VMenu): wrong alignment in RTL mode

[KareemDa]

Description

fixes #12195

Motivation and Context

How Has This Been Tested?

Markup:

<template>
  <v-app id="inspire">
    <v-toolbar>
      <v-toolbar-items style="width: 100%">
        <v-spacer></v-spacer>
        <v-menu offset-y>
          <template v-slot:activator="{ on }">
            <v-btn class="ms-5" v-on="on">
              <span>Menu #2</span>
              <v-icon>mdi-menu-down</v-icon>
            </v-btn>
          </template>

          <v-list>
            <v-list-item>
              <v-list-item-title> item with basic content </v-list-item-title>
            </v-list-item>

            <v-list-item>
              <v-list-item-title>
                item with some of tooo looooong content that wont fit
              </v-list-item-title>
            </v-list-item>

            <v-list-item>
              <v-list-item-title> item with basic content </v-list-item-title>
            </v-list-item>
          </v-list>
        </v-menu>
        <v-spacer></v-spacer>

      </v-toolbar-items>
    </v-toolbar>
  </v-app>
</template>

<script>
export default {
  mounted () {
    this.$vuetify.rtl = true;
  },
}
</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)