Add step in publish pipeline to create PR to azure-sdk-for-net

[Copilot]

This PR adds automation to create a pull request in the Azure SDK for .NET repository that updates the dependency on http-client-csharp when a new version is published.

Implementation Details

1. Created a new script in internal-build-utils package:

   • Added create-azure-sdk-for-net-pr.ts to handle PR creation
   • Added http-client.ts for GitHub API requests
   • Updated the CLI to include a new command for creating PRs

2. Modified the http-client-csharp publish pipeline:

   • Added a new stage that runs after successful publish
   • Calls the PR creation command with proper parameters
   • Only runs on the main branch (not on PRs)

3. Added documentation:

   • Created a CONTRIBUTING.md for http-client-csharp
   • Documented the automated PR creation process and manual fallback

How It Works

When a new version of http-client-csharp is published from the main branch:

1. The script clones the azure-sdk-for-net repository
2. Creates a new branch
3. Updates the Microsoft.TypeSpec.Generator.ClientModel package reference in Directory.Packages.props
4. Creates a PR with appropriate title and description including a link back to the original TypeSpec PR

This automation helps ensure that the Azure SDK for .NET always uses the latest version of the TypeSpec-generated client components, improving consistency across repositories.

Fixes #7110.

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[JoshLove-msft]

Please run pnpm run format on the package directory.

[Copilot]

Please run pnpm run format on the package directory.

Ran pnpm run format on the package directory. The formatter made minor whitespace corrections, removing trailing spaces from the publish.yml file.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• telemetry.astro.build
  • Triggering command: node /home/REDACTED/work/typespec/typespec/website/node_modules/.bin/../astro/astro.js build (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list