feat: add 2 new error entries (runner-environment)

[htekdev]

New Error Entries — July 1, 2026

Adds 2 new runner-environment entries from recent GitHub Issues (June 17–30, 2026 window):

re-519 — Azure Artifacts Credential Provider Removed from Ubuntu Runners

• Source: Azure Artifacts Credential Provider missing on Ubuntu Runner actions/runner-images#14270
• Since: Image build 20260611.554 (June 17, 2026)
• Affected: ubuntu-22.04/24.04/26.04 (and ARM variants), ubuntu-latest, ubuntu-slim
• Error: Value cannot be null. (Parameter 'Path to the Azure Artifacts Credential Provider is null or empty.')
• Fix: Add explicit install-artifacts-credprovider.sh install step before any NuGet restore

re-520 — Windows 11 ARM64 wsl.exe --update Prompt Steals Focus Breaking GUI Automation

• Source: Windows 11 ARM64 image shows WSL update required prompt actions/runner-images#14264
• Since: Late June 2026 image regression
• Affected: windows-11-arm runners using Playwright, Selenium, WinForms/WPF GUI tests in headed mode
• Error: WSL Terminal window spawns on logon and steals foreground focus from test runner
• Fix: Kill WindowsTerminal pre-step, route to windows-latest, or use headless mode

[htekdev]

✅ Approved by Hector for agent merge at 2026-07-07T20:24:58.289Z

The Rocha merge-agent will rebase this PR onto the latest main, wait for CI, and merge when green. This approval persists across rebases.