Update UnbrandedGeneratorVersion to 1.0.0-alpha.20260625.5

[azure-sdk-automation]

This PR updates the UnbrandedGeneratorVersion property in eng/centralpackagemanagement/Directory.Generation.Packages.props and the @typespec/http-client-csharp dependency in eng/packages/http-client-csharp/package.json to version 1.0.0-alpha.20260625.5.

Details

• TypeSpec commit that triggered this PR: microsoft/typespec@9dd6753
• Pipeline run that produced this PR: https://dev.azure.com/azure-sdk/internal/_build/results?buildId=6483329&view=results

Changes

• Updated eng/centralpackagemanagement/Directory.Generation.Packages.props UnbrandedGeneratorVersion property
• Updated eng/packages/http-client-csharp/package.json dependency version
• Ran npm install to update package-lock.json
• Ran eng/packages/http-client-csharp/eng/scripts/Generate.ps1 to regenerate test projects
• Generated emitter-package.json artifacts using tsp-client
• Regenerated SDK libraries using the unbranded emitter via dotnet msbuild /t:GenerateCode

This is an automated PR created by the TypeSpec publish pipeline.

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.