Fix ubuntu CI test job by installing required Tauri Linux system packages

[Copilot]

The test (ubuntu-latest) GitHub Actions job failed while compiling src-tauri because required GTK/GLib WebKit system libraries were not present in the CI image. This change adds the missing Linux dependency installation to the CI test workflow so Rust/Tauri checks can run on Ubuntu.

• Workflow fix: ubuntu-native dependency bootstrap

  • Updated .github/workflows/ci.yml in the test job to install the same Linux packages already required by Tauri builds on Ubuntu.
  • Scoped to Linux runners only (if: runner.os == 'Linux') to avoid affecting Windows behavior.

• What was added

  - name: Install Linux dependencies
    if: runner.os == 'Linux'
    run: sudo apt-get update && sudo apt-get install -y \
      libgtk-3-dev libwebkit2gtk-4.1-dev libayatana-appindicator3-dev librsvg2-dev patchelf

[Knownassa]

Superseded by PR #2, which includes the complete Linux dependency and icon fix.