Extend NuGet package validation

[martincostello]

Use Meziantou.Framework.NuGetPackageValidation.Tool to extend NuGet package validation.

[Copilot]

Pull Request Overview

This PR extends NuGet package validation by integrating Meziantou.Framework.NuGetPackageValidation.Tool alongside the existing dotnet-validate tool. The changes update PowerShell variable references to use proper syntax and restructure the validation workflow to support multiple validation tools.

• Added Meziantou.Framework.NuGetPackageValidation.Tool as a new validation tool
• Updated PowerShell environment variable syntax across multiple files
• Restructured the validation workflow to run both validation tools sequentially

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
.config/dotnet-tools.json	Added Meziantou NuGet package validation tool configuration
.github/workflows/build.yml	Updated workflow to support both validation tools and restructured validation logic
build.ps1	Fixed PowerShell environment variable syntax
.github/workflows/release.yml	Fixed PowerShell environment variable syntax
.github/workflows/bump-version.yml	Fixed PowerShell environment variable syntax

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.59%. Comparing base (4142f79) to head (86f935e).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1045   +/-   ##
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  Coverage   98.59%   98.59%           
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  Files          16       16           
  Lines         284      284           
  Branches       37       37           
=======================================
  Hits          280      280           
  Misses          2        2           
  Partials        2        2           

Flag	Coverage Δ
linux	98.59% <ø> (ø)
macos	97.88% <ø> (ø)
windows	98.59% <ø> (ø)

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