develop pre-release publishing fails: nuget.org rejects push with 403 #1128

• Version: develop (latest published pre-release is 0.6.0-pre.165, Oct 1)
• Target: CI – Build and Publish workflow, 2 / Publish job

Problem

No ElectronNET.Core pre-release has been published from develop since 0.6.0-pre.165 (Oct 1), so changes merged since then (#1116–#1125) aren't available as packages.

The two most recent develop runs pass the integration tests, then fail in the PublishPackages Nuke target when pushing to nuget.org:

Forbidden https://www.nuget.org/api/v2/package/
error: Response status code does not indicate success: 403 (The specified API key is invalid, has expired, or does not have permission to access the specified package.).
Target "PublishPackages" has thrown an exception

• https://github.com/ElectronNET/Electron.NET/actions/runs/42004877216 (Fix host hang when Electron exits before the socket bridge connects #1124)
• https://github.com/ElectronNET/Electron.NET/actions/runs/41983032478 (Fix Electron startup failure caused by the Host lockfile #1125)

The develop runs before that (Oct 18 – Oct 27) failed earlier in integration tests, so Publish never ran and it isn't clear when the key stopped working.

Suggested fix

Rather than generating a new NUGET_API_KEY secret, switch to nuget.org Trusted Publishing, which nuget.org now recommends over API keys for GitHub Actions.

This needs:

1. A Trusted Publishing policy on nuget.org, created by the account or organization that owns the ElectronNET.Core* packages, for repository ElectronNET/Electron.NET and workflow file Build and Publish.yml.
2. A workflow change to request the temporary key in the Publish job.

Why it matters

Pre-releases are the only way to consume develop fixes without building Electron.NET locally.