Bump Microsoft.AspNetCore.TestHost (#3112)

Bumps the dotnet group with 1 update in the /docs/fundamentals/dashboard/automation/aspire-dashboard/Aspire.Dashboard.ScreenCapture directory: [Microsoft.AspNetCore.TestHost](https://github.com/dotnet/aspnetcore).


Updates `Microsoft.AspNetCore.TestHost` from 9.0.3 to 9.0.4
- [Release notes](https://github.com/dotnet/aspnetcore/releases)
- [Changelog](https://github.com/dotnet/aspnetcore/blob/main/docs/ReleasePlanning.md)
- [Commits](dotnet/aspnetcore@v9.0.3...v9.0.4)

---
updated-dependencies:
- dependency-name: Microsoft.AspNetCore.TestHost
  dependency-version: 9.0.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: dotnet
...

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Author: dependabot[bot]