upgrade ubuntu 20.04 to 24.04

[YanaXu]

Description

Mandatory Checklist

• Please choose the target release of Azure PowerShell. (⚠️Target release is a different concept from API readiness. Please click below links for details.)

  • General release
  • Public preview
  • Private preview
  • Engineering build
  • No need for a release

• Check this box to confirm: I have read the Submitting Changes section of CONTRIBUTING.md and reviewed the following information:

• SHOULD update ChangeLog.md file(s) appropriately
  • Update src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md.
    • A snippet outlining the change(s) made in the PR should be written under the ## Upcoming Release header in the past tense.
  • Should not change ChangeLog.md if no new release is required, such as fixing test case only.
• SHOULD regenerate markdown help files if there is cmdlet API change. Instruction
• SHOULD have proper test coverage for changes in pull request.
• SHOULD NOT adjust version of module manually in pull request

[azure-client-tools-bot-prd]

Thanks for your contribution! The pull request validation has started. Please revisit this comment for updated status.

[Copilot]

Pull Request Overview

This PR upgrades the Docker base image from Ubuntu 20.04 to Ubuntu 24.04 for the Azure PowerShell container. The changes update all references to the Ubuntu version throughout the Dockerfile to maintain consistency with the new base image.

• Updates the base PowerShell image from ubuntu-20.04 to ubuntu-24.04
• Updates the Azure PowerShell image name to reflect the new Ubuntu version
• Updates the environment variable to indicate the correct Ubuntu version

[vidai-msft]

LGTM