Restore ubuntu-latest for native hosting validation once Playwright supports Ubuntu 26.04 #22216

Is there an existing issue for this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe the problem.

The native_hosting job in .github/workflows/native-hosting-validation.yml is temporarily pinned to:

runs-on: ubuntu-24.04

This workaround was introduced in #22207 because ubuntu-latest selected Ubuntu 26.04, while eng/scripts/test-native-hosting.sh installs playwright@1.58.2. Browser setup fails with:

Cannot install dependencies for ubuntu26.04-x64 with Playwright 1.58.2!
Error: ERROR: Playwright does not support chromium on ubuntu26.04-x64

The preceding 134 C# tests passed. Playwright is required by the later workload, revision, and CLI Dashboard smoke scenarios, so removing browser installation would drop coverage rather than fix the compatibility problem.

Describe the solution you'd like

Once Playwright supports the Ubuntu image selected by ubuntu-latest:

• Update the pinned Playwright version in eng/scripts/test-native-hosting.sh as needed.
• Switch the native_hosting job back to runs-on: ubuntu-latest and remove its temporary compatibility comment.
• Preserve all existing smoke scenarios and browser assertions; do not quarantine or skip them to work around runner compatibility.
• Validate the real GitHub Actions run: confirm the selected runner image, successful Chromium dependency/browser installation, and execution of workload-dashboard-smoke, revision-dashboard-smoke, and cli-dashboard-smoke, including their cleanup checks.

Additional context

• Original failure: https://github.com/microsoft/aspire/actions/runs/43288780023/job/131429152657?pr=22207
• Temporary pin: Separate channel update validation with aspire update --dry-run #22207, commit ec1c773f6d.
• Playwright 1.58.2's supported native dependencies include Ubuntu 24.04: https://github.com/microsoft/playwright/blob/v1.58.2/packages/playwright-core/src/server/registry/nativeDeps.ts