Update Microsoft.OpenApi to 2.7.5

[martincostello]

• Update Microsoft.OpenApi in shipping packages to 2.7.5 to pick up fix for GHSA-v5pm-xwqc-g5wc.
• Update Microsoft.OpenApi for tests to 2.7.6.
• Update meziantou.framework.nugetpackagevalidation.tool, ReportGenerator and Verify.XunitV3 to their latest versions.

Resolves #3973.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.04%. Comparing base (8457418) to head (d070934).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3974   +/-   ##
=======================================
  Coverage   95.04%   95.04%           
=======================================
  Files         111      111           
  Lines        3958     3958           
  Branches      801      801           
=======================================
  Hits         3762     3762           
  Misses        196      196           

Flag	Coverage Δ
Linux	95.04% <ø> (ø)
Windows	95.04% <ø> (ø)
macOS	95.04% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[Copilot]

Pull request overview

This PR updates dependency versions to address a deprecated Microsoft.OpenApi reference (per #3973) and refreshes a few tooling/test dependencies.

Changes:

• Bump Microsoft.OpenApi in shipping packages from 2.4.1 to 2.7.5 via VersionOverride.
• Update centrally managed package versions for Microsoft.OpenApi / Microsoft.OpenApi.YamlReader to 2.7.6 and bump ReportGenerator / Verify.XunitV3.
• Update meziantou.framework.nugetpackagevalidation.tool dotnet tool version to 1.0.53.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
src/Swashbuckle.AspNetCore.Swagger/Swashbuckle.AspNetCore.Swagger.csproj	Updates the shipping package’s Microsoft.OpenApi VersionOverride to 2.7.5.
src/Swashbuckle.AspNetCore.ApiTesting/Swashbuckle.AspNetCore.ApiTesting.csproj	Updates the packable ApiTesting package’s Microsoft.OpenApi VersionOverride to 2.7.5.
Directory.Packages.props	Bumps centrally managed versions for Microsoft.OpenApi*, ReportGenerator, and Verify.XunitV3.
.config/dotnet-tools.json	Updates the NuGet package validation dotnet tool version.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.