Create foundation for Labgrid-based OS tests (#2812)

* Create foundation for Labgrid-based OS tests

Add foundation for Labgrid-based tests of OS builds. Currently uses just
the QEMU driver, which starts a virtual machine with pristine OS, and
generates few log reports which are saved as build artifacts.

Workflow is currently triggered either manually by specifying an OS
version, or by OS build job, which now saves an artifact of the OVA
image. This allows for some modularity. If we eventually add the
possibility to run builds on PRs, we could also add the workflow_call
trigger and turn the workflow into a reusable one.

TBD (in future PRs): some meaningful tests and possibility to test on
real hardware (either local or distributed).

* Apply suggestions from @agners

Co-authored-by: Stefan Agner <stefan@agner.ch>

* Wrap test command in a script, create venv for local tests

* Make shellcheck happy

---------

Co-authored-by: Stefan Agner <stefan@agner.ch>

.github/workflows/test.yaml

@@ -0,0 +1,92 @@
+name: Test HAOS image
+run-name: "Test HAOS ${{ inputs.version || format('(OS build #{0})', github.event.workflow_run.run_number) }}"
+
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: Version of HAOS to test
+        required: true
+        type: string
+
+  workflow_run:
+    workflows: ["OS build"]  # must be in sync with build workflow `name`
+    types:
+      - completed
+
+jobs:
+  test:
+    if: ${{ github.event_name != 'workflow_run' || github.event.workflow_run.conclusion == 'success' }}
+
+    env:
+      NO_KVM: 1
+
+    name: Test in QEMU
+    runs-on: ubuntu-22.04
+    defaults:
+      run:
+        working-directory: ./tests
+    steps:
+      - name: Install system dependencies
+        run: |
+          sudo apt update
+          sudo apt install -y qemu-system-x86 ovmf
+
+      - name: Checkout source
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+
+      - name: Setup Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: 3.12
+
+      - name: Install Python requirements
+        run:
+          pip install -r requirements.txt
+
+      - name: Download HAOS image
+        if: ${{ github.event_name == 'workflow_dispatch' }}
+        run: |
+          curl -sfL -o haos.qcow2.xz  https://os-artifacts.home-assistant.io/${{github.event.inputs.version}}/haos_ova-${{github.event.inputs.version}}.qcow2.xz
+
+      - name: Get OS image artifact
+        if: ${{ github.event_name == 'workflow_run' }}
+        uses: dawidd6/action-download-artifact@v2
+        with:
+          workflow: build.yaml
+          workflow_conclusion: success
+          name: ova-image
+
+      - name: Extract OS image
+        run: |
+          unxz haos.qcow2.xz
+
+      - name: Run tests
+        run: |
+          ./run_tests.sh
+
+      - name: Archive logs
+        uses: actions/upload-artifact@v3
+        if: always()
+        with:
+          name: logs
+          path: |
+            lg_logs/*
+
+      - name: Archive JUnit reports
+        uses: actions/upload-artifact@v3
+        if: always()
+        with:
+          name: junit_reports
+          path: |
+            junit_reports/*.xml
+
+      - name: Publish test report
+        uses: mikepenz/action-junit-report@v4
+        if: always()
+        with:
+          report_paths: 'junit_reports/*.xml'
+          annotate_only: true
+          detailed_summary: true