PR Summary

This pull request includes updates to the CHANGELOG/7.4.md file for the 7.4.8 release, which is an internal-only release. The changes involve several build and packaging improvements. Below are the most important changes:

Build and Packaging Improvements:

• Added a new section for the 7.4.8 release, specifying that it is internal only and not available for download.
• Updated the .NET SDK to version 8.0.406 and made various improvements to the release pipeline, including adding a UseDotnet task and fixing MSIX stage issues.
• Converted multiple CI pipelines (PowerShell-CI-macos, PowerShell-CI-linux, PowerShell-Windows-CI) to GitHub Actions.
• Added EV2 support for publishing PowerShell packages to PMC and fixed related parse state issues.
• Removed AzDO credscan as it is now integrated into GitHub and updated CODEOWNERS.

PR Context

PR Checklist

• PR has a meaningful title
  • Use the present tense and imperative mood when describing your changes
• Summarized changes
• Make sure all .h, .cpp, .cs, .ps1 and .psm1 files have the correct copyright header
• This PR is ready to merge and is not Work in Progress.
  • If the PR is work in progress, please add the prefix WIP: or [ WIP ] to the beginning of the title (the WIP bot will keep its status check at Pending while the prefix is present) and remove the prefix when the PR is ready.
• Breaking changes
  • None
  • OR
  • Experimental feature(s) needed
    • Experimental feature name(s):
• User-facing changes
  • Not Applicable
  • OR
  • Documentation needed
    - [ ] Issue filed:
• Testing - New and feature
  • N/A or can only be tested interactively
  • OR
  • Make sure you've added a new test if existing tests do not effectively test the code changed
• Tooling
  • I have considered the user experience from a tooling perspective and don't believe tooling will be impacted.
  • OR
  • I have considered the user experience from a tooling perspective and opened an issue in the relevant tool repository. This may include:
    • Impact on PowerShell Editor Services which is used in the PowerShell extension for VSCode
      (which runs in a different PS Host).
      • Issue filed:
    • Impact on Completions (both in the console and in editors) - one of PowerShell's most powerful features.
      • Issue filed:
    • Impact on PSScriptAnalyzer (which provides linting & formatting in the editor extensions).
      • Issue filed:
    • Impact on EditorSyntax (which provides syntax highlighting with in VSCode, GitHub, and many other editors).
      • Issue filed: